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Laboratory Standard & Design Guidelines

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Last updated: November 19, 2021

The Stanford Laboratory Standard & Design Guide is a resource document for use by faculty, staff, and design professionals during the planning and early design phases of a project. This Guide is to be used in conjunction with Stanford’s Facilities Design Guidelines and applies to construction projects for all Stanford University facilities, including leased properties.

The Stanford Laboratory Standard & Design Guide is not “all inclusive.” It does not cover all regulatory issues nor does it cover all design situations. It is important to note that use practices must be considered during the design process, as they can directly influence how the laboratory will be designed. In all cases, EH&S should be consulted on questions regarding health, safety, and the environment.

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Last updated: November 19, 2021

Laboratory Standard & Design Guidelines

The Stanford Laboratory Standard & Design Guide is a resource document for use by faculty, staff, and design professionals during the planning and early design phases of a project. This Guide is to be used in conjunction with Stanford’s Facilities Design Guidelines and applies to construction projects for all Stanford University facilities, including leased properties.

The Stanford Laboratory Standard & Design Guide is not “all inclusive.” It does not cover all regulatory issues nor does it cover all design situations. It is important to note that use practices must be considered during the design process, as they can directly influence how the laboratory will be designed. In all cases, EH&S should be consulted on questions regarding health, safety, and the environment.


1Introduction

1.1Purpose

Stanford University has a continuing need to modernize and upgrade its facilities. The resulting construction projects often have significant health and safety requirements due to regulatory oversight. Since these requirements can impact the design of a project, Environmental Health and Safety (EH&S) prepared this EH&S Laboratory Design Guide to aid the campus community with planning and design issues. EH&S believes that the Guide, in conjunction with EH&S’s plan review and consultation, improves design efficiency and minimizes changes.

1.2Application

The Guide is a resource document for use by faculty, staff, and design professionals for use during the planning and early design phases of a project. The Guide applies to construction projects for all Stanford University facilities, including leased properties.

1.3Format of the Guide

The Guide is formatted to address laboratory design issues pertinent to General Laboratories (e.g., chemical laboratories) in Section 1, with additional requirements for Radioactive Materials Laboratories and Biosafety Level 2 Laboratories presented in Sections 2 and 3 respectively.

Within the sections, specific design criteria are provided. Comments are included under the specific design criterion to give the user the rational behind the design feature.

1.4References

References include regulations (e.g., Cal/OSHA and Fire Code), concensus standards (e.g., ANSI/ASHRAE), and good practices. Good practices stem from industry standards and/or the judgement/knowledge of Standard University’s EH&S professionals.

Design criteria are designated in the following ways:

Shall:  

Criterion is mandated by applicable regulation(s).

  • The user of the Guide is required to include the design feature.

Must:

Criterion is based on well-established consensus standards/guidelines. “Must” is used to reflect a Stanford requirement, although not required by a regulation.

  • The user of the Guide is required to include the design feature.

Should:

Criterion is advisory in nature, based on good engineering and safety practices.

  • It is left to the discretion of the user of the Guide to include the design feature.

1.5Limitations of the Guide

The EH&S Laboratory Design Guide is not “all inclusive.” It does not cover all regulatory issues nor does it cover all design situations. It is important to note that use practices must be considered during the design process, as they can directly influence how the laboratory will be designed (e.g., how hazardous materials are used impacts how they are stored, which is a design issue). In all cases, EH&S should be consulted on questions regarding health, safety, and environment.

1.6Acknowledgement

The majority of this document was adapted from the University of California Environmental Health and Safety Laboratory Safety Design Guide. Stanford University Environmental Health & Safety expresses great appreciation to University of California for all initial efforts put forth in its original development.


2General Requirements For Stanford University Laboratories

2.1Regulations, Standards and References

Regulations, Standards and References

Regulations:

  • Federal Code of Regulations (CFR), Title 29, Labor
  • California Code of Regulations (CCR), Title 8, Cal/OSHA Standards
  • California Code of Regulations (CCR), Title 24, Part 9, Uniform Fire Code
  • California Code of Regulations, Title 24, Part 2, California Building Code
  • CDC Select Agents, Title 42, Chapter I, Part 72 – Interstate Shipment of Etiologic Agents
  • National Fire Protection Association (NFPA) Handbook 70: National Electric Code
  • California Radiation Control Regulations, Title 17
  • Palo Alto Municipal Code, Title 16, Building Regulations
  • County of Santa Clara Municipal Code Section B11, Chapters XIII and XIV, Hazardous Material and Toxic Gas Storage

Consensus Standards and References:

  • American National Standard for Laboratory Ventilation (ANSI/AIHA Z9.5-2012)
  • American National Standard for Thermal Environmental Conditions for Human Occupancy (ANSI/ASHRAE 55-1992)
  • State of California, Department of Health Services, Radiologic Health Branch,
  • Guide for the Preparation of Applications for Medical Programs (RH 2010 4/90) (not formally adopted)
  • “Safe Handling of Radioactive Materials”, National Council on Radiation Protection (NBS Handbook 92)
  • “Safe Handling of Radionuclides”, International Atomic Energy Agency, Safety Series No. 1, (1973 ed. is still current as of 1999) (IAEA)
  • CDC-NIH Biosafety in Microbiological and Biomedical Laboratories, 5th Edition
  • National Institutes of Health Design Requirements Manual, December 12, 2016
  • National Research Council (2011) Prudent Practices in the Laboratory

2.2Scope

The primary objective in laboratory design is to provide a safe environment for laboratory personnel to conduct their work. A secondary objective is to allow for the maximum flexibility for safe research use. Undergraduate teaching laboratories require other specific design considerations. Therefore, all health and safety hazards must be anticipated and carefully evaluated so that protective measures can be incorporated into the design. No matter how well designed a laboratory is, improper usage of its facilities will always defeat the engineered safety features. Proper education of the facility users is essential.

The General Requirements listed in this section illustrate some of the basic health and safety elements to include in all new and remodeled laboratories at Stanford. Variations from these guidelines need approval from SU Environmental Health and Safety (EH&S). The subsections of Section 1.0 provide specific guidance on additional critical features of a general laboratory (e.g., fume hoods, hazardous materials storage, and compressed gases.)

2.3Building Requirements

1.  Designer Qualifications- The designer must have the appropriate professional license in his/her area of expertise.

Good Practice

2.  Building Occupancy Classification- Occupancy classification is to be based upon an assessment of a projected chemical inventory of the building. Prior to the final design, the campus fire safety organization will need to assign an occupancy class to ensure compliance with the building codes.

24 CCR, Part 2 (California Building Code)

24 CCR, Part 9 (California Fire Code)

3.  Environmental Permits- Project managers must consult with SU EH&S to identify permitting and pollution abatement engineering  requirements for the building. This should be done well before key resource allocation decisions are made.

2.4Building Design Issues

Because the handling and storage of hazardous materials inherently carries a higher risk of exposure and injury, it is important to segregate laboratory and non-laboratory activities. In an academic setting, the potential for students to need access to laboratory personnel, such as instructors and assistants, is great. A greater degree of safety will result when nonlaboratory work and interaction is conducted in a space separated from the laboratory.

1.  Special consideration should be given to the choice of fireproof construction for the buildings. The selection of the site shall be such to minimize the risk of landslide or flood damage.

Safe Handling of Radionuclides 1973 Edition Section 3.3.1
Good practice per Stanford University EH&S

2.  An automatically triggered main gas shutoff valve for the building shall be provided for use in a seismic event. In addition, interior manual shutoff valves shall be provided for both research and teaching areas.

Good Practice per Stanford University EH&S

3.  Large sections of glass shall be shatter resistant.

Good Practice per Stanford University EH&S

In the event of a severe earthquake, as the glass in cabinets and windows breaks, the shards need to be retained to prevent injury.

4.  Offices and write-up desks for laboratory personnel should be located outside of the laboratory space. Locating the office zones very close to the laboratory, preferably within the line of sight achieved via the use of glass walls or walls with viewing windows, will provide easy access, visibility, and communication.

  • Locating offices and write-up desks outside the laboratory environment allows for a safer workspace where food can be consumed, quiet work can be done, and more paper and books can be stored.

Where it is necessary to have offices or write-up desks within research areas, there must be adequate separation between the laboratory area and the office areas.

  • Adequate separation can be achieved through a combination of distance and/or physical barriers (e.g., partitions or walls), such that Personal Protective Equipment (PPE) is not required while sitting at desks. Different flooring between the office and laboratory zones is desirable, as it can provide a visual cue between the office/write- up desk area of the lab and the area where hazardous materials are used and stored.
  • When write-up desks are located within the laboratory, they must be at the entrance of the laboratory, with the wet lab benches, fume hoods, biosafety cabinets, and equipment using or storing chemicals, biological materials, and radioactive materials located on the opposite side of the laboratory; this allows laboratory personnel and visitors to enter the laboratory without traveling through the hazardous materials zone of the lab.

It is important to segregate laboratory and non-laboratory activities because (1) the handling and storage of hazardous materials inherently carries a higher risk of exposure and injury; (2) the egress path from a lab desk to an exit should not require movement through a more hazardous zone; and (3) it is prohibited to store, consume food, apply make-up or chew gum in areas where hazardous materials are used and/or stored.

National Research Council, Prudent Practices in the Laboratory, Chapter 9.B (2011)
DiBerardinis, Louis, et al. Guidelines for Laboratory Design, Chapter 2.1.1.4 (2013)
National Institutes of Health Design Requirements Manual (December 12, 2016) Sections 2.1.3.5, 2.2.4.1
Cal/OSHA Standard 5191, Appendix A, Occupational Exposure to Hazardous Chemicals in Laboratories
California Radioactive Material License, 0676-43

2.5Laboratory Design Considerations

Walls/Doors/Security

1.  The laboratory shall be completely separated from outside areas (i.e., must be bound by four walls).

California Radiation Control Regulations, Title 17 
State of California, Department of Health Services, Radiologic Health Branch 
Guide for the Preparation of Applications for Medical Programs (RH 2010 4/90) 

Having enclosed laboratories will help contain spills, keep unauthorized personnel from entering areas where hazardous operations are performed, etc. These regulations apply specifically to laboratories containing radioactive materials; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry and electronics).

2.  The laboratory shall have means of securing specifically regulated materials such as DEA (Drug Enforcement Administration) controlled substances and CDC (Centers for Disease Control) select agents and radioactive materials (i.e., lockable doors, lockable cabinets, etc.).

CDC Select Agents 
Controlled Substances Act, Section 803 
California Radiation Control Regulations, Title 17 
State of California, Department of Health Services, Radiologic Health Branch, 
Guide for the Preparation of Applications for Medical Programs (RH 2010 4/90) 

Having secured hazardous materials storage will keep unauthorized personnel from gaining access to them. These regulations apply specifically to laboratories containing radioactive materials and CDC Select Agents; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry and electronics).

Windows

3.  If the laboratory has windows that open, they must be fitted with insect screens.

CDC-NIH Biosafety in Microbiological and Biomedical Laboratories (BSL 2, D.5) 
Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines) Appendix Physical Containment-II-B-4-e: Physical Containment/Laboratory Facilities (BL2)

Insects, particularly flies, are known to be a potential carrier of disease. To keep insects out of the lab, the doors must be closed while an experiment is in progress, and windows shall be screened if they are capable of being opened. These references apply specifically to laboratories containing biological materials; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry and electronics).

Flooring

4.  The floor must be non-pervious, one piece, and with covings to the wall. This can be achieved by use of glue, heat welded vinyl flooring, epoxy coated concrete slab, etc. 

NBS Handbook 92 
IAEA, Safe Handling of Radionuclides 
Guide for the Preparation of Applications for Medical Programs (RH 2010 4/90) 

Floors should be coved up walls and cabinets to ensure spills cannot penetrate underneath floors/cabinets. Tiles and wooden planks are not appropriate because liquids can seep through the small gaps between them. These references apply specifically to laboratories containing biological and radioactive materials; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry, electronics, etc.).

5.  Floors in storage areas for corrosive liquids shall be of liquid tight construction. 

CCR, Title 24, Part 9, Sections 8003.1.7.2, 8003.14.1.2 

Sinks

6.  Each laboratory must contain a sink for handwashing. 

CDC-NIH Biosafety in Microbiological and Biomedical Laboratories (BSL 2, D.1) 
Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines) Appendix Physical Containment-II-B-4-dPhysical Containment/Laboratory Facilities (BL2)
NBS Handbook 92 
IAEA, Safe Handling of Radionuclides 

Exposure to hazardous materials and/or pathogenic organisms can occur by hand-to-mouth transmission. It is extremely important that hands are washed prior to leaving the laboratory. For this very reason, the sink should be located close to the egress. These references apply specifically to laboratories containing biological and radioactive materials; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry and electronics).

7.  Laboratory sinks shall have lips that protect sink drains from spills.

P.A. Ordinance. 16.09.032(b)(13) 

Sink lips or berms should be >= 0.25 inches and designed to completely separate the lab bench or fume hood work area from the sink drain.

Chemical/Waste Storage

8.  Chemical storage shelves shall not be placed above laboratory sinks.

P.A. Ordinance, 16.09.091 

9.  Sufficient space or facilities (e.g., storage cabinets with partitions) shall be provided so that incompatible chemicals/gases (waste and non-waste) can be physically separated and stored. This will be based on the chemical inventory and use projection provided by the Principal Investigator to the project and EH&S. If the project scope cannot provide sufficient storage the user must develop a written management control plan to include as part of their local Chemical Hygiene Plan.

Good Practice per Stanford University EH&S 
CCR, Title 24, Part 9, Section 8001.9.8 

Materials which in combination with other substances may cause a fire or explosion, or may liberate a flammable or poisonous gas, must be kept separate. When designing the shelves, it is important to factor in enough space for secondary containers. Recommend that solvent storage not be located under the laboratory fume hood, as this is a location where fires are most likely to occur in laboratories.

All labs should be designed to conveniently and safely accommodate the temporary storage of biological, radiological, and chemicals (non-waste and waste) based on laboratory use projections. Wastes are generally stored in the lab in which they are generated, not in centralized accumulation areas.

Furniture Design, Location, and Exit Paths

10.  All furniture must be sturdy. All work surfaces (e.g., bench tops and counters) must be impervious to the chemicals used. The counter top should incorporate a lip to help prevent run-off onto the floor. 

NBS Handbook 92 
IAEA, Safe Handling of Radionuclides 
Guide for the Preparation of Applications for Medical Programs (RH 2010 4/90) 
CDC-NIH Biosafety in Microbiological and Biomedical Laboratories (BSL 2, D.3) 
Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines) Physical Containment-II-B-4-b : Physical Containment/Laboratory Facilities (BL2)

For example, many microbiological manipulations involve concurrent use of chemical solvents such as formaldehyde, phenol, and ethanol as well as corrosives. The lab bench must be resistant to the chemical actions of these substances and disinfectants. Wooden bench tops are not appropriate because an unfinished wood surface can absorb liquids. Also, wood burns rapidly in the event of a fire. Fiberglass is inappropriate since it can degrade when strong disinfectants are applied. Fiberglass also releases toxic smoke when burned. These references apply specifically to laboratories containing biological and radioactive materials; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry and electronics).

11.  Vented cabinets with electrical receptacles and sound insulation should be provided for the placement of individual vacuum pumps where their use is anticipated. A one- to two-inch hole for the vacuum line hose from the cabinet to the bench top should be provided.

Good Practice

12.  The lab shall have a minimum aisle clearance of at least 24 inches. Main aisles used for emergency egress must have a clearance width of at least 36 inches. 

CCR Title 8, 3272(b) 
NFPA 45, Standard on Fire Protection for Laboratories 

Clear aisles and exits are necessary to facilitate departure in the event of an emergency. In practice, lab aisles must be designed wider than 24” so that even with the presence of lab stools and other miscellaneous items, a clearance of 24” is always maintained.

13.  A pathway clearance of 36 inches must be maintained at the face of the access/exit door. 

Good Practice per Stanford University EH&S 

Lab benches must not impede emergency access to an exit. This is also applicable to placement of other furniture and appliances such as chairs, stools, refrigerators, etc.

14.  Designated storage space should be provided for lab carts. Location must not reduce width of corridors or aisles to less than code-required widths. Lab carts should be secured with earthquake restraints when not in use. 

Good practice per Stanford University EH&S. see also information on “Earthquake Restraints” below. 

15.  Furniture design must comply with basic ergonomic specifications referenced in the SU Facilities Design and Construction Standards (Section 01310, Part A – 1.04) 

Good Practice 

Lack of properly designed workstations can increase safety and ergonomic risks for occupants.

16.  Laboratory shelving should NOT be installed at heights and distances which require workers to reach 30 centimeters above shoulder height and extend arms greater than 30 centimeters while holding objects 16 kg or less when standing on the floor or on a 12” step stool. 

ACGIH Threshold Limit Values for Chemicals Substances and Physical Agents & Biological Agents 
Good practice per Stanford University EH&S. 

Installation of high shelving, above laboratory benches in particular, can create several potential hazards, including, but not limited to ergonomic issues (over reaching above shoulders and across lab benches); spill and exposures to chemical, radiological or biological agents (e.g., dropping containers when accessing them at high levels). If high shelving were installed, administrative controls, which are often burdensome, would be required. A system for ensuring safe access would include prohibition on the materials stored on shelves, limitations on the frequency of use, availability of ladders or ladders stands, training on ladders, etc. (See also #15 and “Earthquake Restraint” information below.)

17.  The space between adjacent workstations and laboratory benches should be 5 ft. or greater to provide ease of access. In a teaching laboratory, the desired spacing is 6 ft. Bench spacing shall be considered and included in specifications and plans. 

Americans with Disabilities Act of 1990 (ADA) 
Title I, “Employment,” Sec. 101, “Definitions,” 42 USC 12111 9(A) 
Title III, “Public Accommodations and Services Operated by Private Entities,” Sec. 303, New Construction and
Alterations in Public Accommodations and Commercial Facilities,” 42 USC 12183. 
NFPA 45, Chapters 2 and 3 

18.  The laboratory doors shall be automatically self-closing. Such self-closing doors are to be able to be opened with a minimum of effort as to allow access and egress for physically challenged individuals. 

24 CCR, Part 2, Chap. 10 
24 CCR, Part 9 1007.4.4 
Americans with Disabilities Act of 1990 (ADA) 
Title III, “Public Accommodations and Services Operated by Private Entities,” Sec. 303, New Construction and
Alterations in Public Accommodations and Commercial Facilities,” Pt. 36, Appendix A
Prudent Practices in the Laboratory, 5.C 

19.  Doors in H-occupancy laboratories shall have doors which swing in the direction of egress. Doors serving B-occupancy shall swing in the direction of egress if the occupant load is 50 or more. Where possible, all B-occupancy lab doors should swing out. 

1997 California Building Code

Doors which swing in the direction of egress will facilitate occupant departures from laboratories during emergencies.

20.  Sufficient space or facilities must be provided for the storage, donning and doffing of personal protective equipment used in the laboratory.

National Institutes of Health Design Requirements Manual (December 12, 2016) Section 2.1.3.5
Good practice per Stanford University EH&S

Facilities such as hooks or cabinets for lab coats, containers for safety eyewear and/or hearing protection, must be provided so that personnel are able to don and doff the personal protective equipment (PPE) before entering and exiting the hazardous areas of the laboratory. PPE storage should be separate from any storage provided for ordinary clothing.

Illumination

21.  Laboratory areas shall be provided adequate natural or artificial illumination to ensure sufficient visibility for operational safety.

NUREG 1556 Vol. 7 Appendix K
Safe Handling of Radionuclides, Section 3.3.5 (1973 ed.) 
State of California, Department of Health Services, Radiologic Health Branch, Guide for the Preparation of
Applications for Medical Programs (RH 2010 4/90) 
Title 8, 3317, Illumination 

Earthquake Restraints

22.  All equipment requiring anchoring shall be anchored, supported and braced to the building structure in accordance with CCR Title 24, Part 2, Table 16A-O. For example, any equipment, including but not limited to, appliances and shelving that are 48 inches or higher and have the potential for falling over during an earthquake, shall be permanently braced or anchored to the wall and/or floor. 

California Code of Regulations (CCR), Title 24, Part 2, Table 16A-O, California Building Standards Commission (2007)

California Code of Regulations (CCR), Title 8, 3241, California Building Standards Commission (2007)

This practice keeps these items from falling in the event of an earthquake and assures that safety while exiting is not compromised.

23.  A channeled anchoring station for seismic bracing of equipment, named the Universal Restraining Bar, shall be installed along all bench top/counters in laboratories and other horizontal surfaces that house equipment. These bars shall be installed at the back edge of the bench to minimize bench space used. Examples and guidance are provided on the ProtectSU website protectsu.stanford.edu. This system will allow a bracing point for all bench top equipment and will provide standard bracing locations for all benchtop equipment. This bar allows for bracing of items in a way that allows them to be moved to another location when needed, and re-braced after moving. The bar should be adhered to the benchtop with very high bond adhesive so that no holes are drilled. 

ProtectSU, Stanford’s Seismic Mitigation Initiative, protectsu.stanford.edu 

24.  All shelves must have a passive restraining system to adequately prevent shelf contents from toppling over. Seismic shelf lips (3/4 inch or greater), sliding doors, or mesh nets are examples. The shelves themselves must be firmly fixed so they cannot be vibrated out of place and allow shelf contents to fall. 

Prudent Practices in the Laboratory (2011 edition), 3.B.1.4 and 5.E.2
Good Practice per Stanford University EH&S 

Installation of seismic lips on shelving areas will prevent stored items from falling during a seismic event. For bookshelves, friction matting may be substituted upon consultation with EH&S.

25.  All equipment requiring anchoring, whether installed by a contractor or the University, shall be anchored, supported, and braced to the building structure in accordance with 24 CCR Part 2, Table 16A-O.

CCR, Title 24, Part 2 Table 16A-O 

26.  Cabinets must be equipped with positive locking door latches. 

FEMA, Reducing the Risks of Nonstructural Earthquake Damage

Examples include barrel bolts, safety hasps, and child proof locks. These latches will not allow the cabinet door to open unless the locking mechanism is triggered. Magnetic or pinch grip catches are not considered “positive locking” and hence should not be used.

Cleanability

27.  The laboratory shall be designed so that it can be easily cleaned. Bench tops must be a seamless one-piece design to prevent contamination. Laminate bench tops are not suitable. Penetrations for electrical, plumbing, and other considerations must be completely and permanently sealed. If the bench abuts a wall, it must be coved or have a backsplash against the wall. Walls should be painted with washable, hard non-porous paints. 

CDC-NIH Biosafety in Microbiological and Biomedical Laboratories, (BSL 2, D.2) 
Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines) Appendix Physical Containment-II-B-4-aPhysical Containment/Laboratory Facilities (BL2)
NBS Handbook 92 
IAEA, Safe Handling of Radionuclides

Wooden and wood finish walls or floors are not appropriate because they can absorb hazardous and/or potentially infectious material, particularly liquids, making decontamination/remediation virtually impossible. These references apply specifically to laboratories containing biological and radioactive materials; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry and electronics).

28.  Spaces between benches, cabinets, and equipment must be accessible for cleaning and allow for servicing of equipment. 

CDC-NIH Biosafety in Microbiological and Biomedical Laboratories (BSL 2, D.4) 
Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines) Appendix Physical Containment-II-B-4-c : Physical Containment/Laboratory Facilities (BL2)

Laboratory furniture must have smooth, non-porous surfaces so as to resist the absorption of liquids and the harsh effects of disinfectants. Furniture must not be positioned in such a manner that makes it difficult to clean spilled liquids or conduct routine maintenance. For example, positioning a Class II biosafety cabinet in a limited concave space might not allow the biosafety cabinet certifier to remove panels of the cabinet when recertifying the unit. These references apply specifically to laboratories containing biological and radioactive materials; however, Stanford University EH&S interprets this to include all laboratories (e.g., general chemistry and electronics).

Breakrooms

29.  The design of the laboratory building must incorporate adequate additional facilities for food storage/consumption and personal hygiene tasks.

California Radioactive Material License, 0676-43 
State of California, Department of Health Services, Radiologic Health Branch – DOHS 2010
Stanford University Radiation Safety Manual 

Per 8 CCR 3368(b), 5193(d)(2), the storage and consumption of food, application of cosmetics or lip balm, or handling of contact lens in areas they may be contaminated by any toxic material or bloodborne pathogen is prohibited.

2.6Mechanical Considerations

Electrical

30.  Shall provide GFI protection to electrical receptacles above counter tops and within 6 feet of sinks. Receptacles that are not readily accessible or receptacles for appliances occupying dedicated space, which are cord-and-plug connected in accordance with NEC Section 400-7A(6-8), are exempted. 

NFPA 70, Chapter 2, 210-8 

31.  The lab should be fitted with an adequate number of electrical outlets, which can accommodate electrical current requirements with an additional 20-40% capacity. 

Good Practice per Stanford University

The lab may have several pieces of equipment, which require large amounts of electrical current. Such items include freezers, biosafety cabinets, centrifuges, and incubators. The room design must take into consideration concerns such as electrical demand prior to occupancy to avoid a potential power failure.

32.  Circuit breakers should be located outside the lab, but not in rated corridors. 

Good Practice per Stanford University EH&S

In the event of an emergency, the laboratory may be unsafe to enter. Hence, the circuit breakers for key electrical appliances should be located outside the lab. ICBO recommends not putting electrical panels in rated corridors.

Plumbing 

33.  Auxiliary valves for gas and vacuum lines should be located outside the lab. 

Good Practice per Stanford University EH&S

In the event of an emergency, the laboratory may be unsafe to enter. Hence, the valves for gas and vacuum lines should be located outside the lab.

34.  Flexible connections should be used for connecting gas and other plumbed utilities to any freestanding device, including but not limited to biosafety cabinets, incubators, and liquid nitrogen freezers. Flexible connections should be appropriate for the pressure requirements and should be constructed of material compatible with the transport gas. A shutoff valve should be located within sight of the connection and clearly marked. 

Good Practice per Stanford University EH&S

Seismic activity may cause gas and other utility connections to break off. A flexible connection will minimize this potential considerably. 

35.  Sink drains traps shall be transparent (e.g., made of glass) and easy to inspect or have drain plugs to facilitate mercury spill control.

P.A. Ordinance, 16.09.032(b)(14)

If mercury-containing products or compounds will not be used, an exemption may be requested in writing to; Stanford University Environmental Quality Manager, Stanford Utilities Department, Mail Code 7270.

36.  Lab waste water lines shall be separate from domestic sewage, and a sampling point shall be installed in an easily accessible location outside the building.

P.A. Ordinance, 16.09.060

The sampling point shall be installed at a location where all building lab wastes are discharged, before the lab waste line connects to the domestic waste line. The sampling point shall be designed so that it is perpendicular to the lab waste line, has a minimum 4 inch diameter, has a cleanout screw on cap and is protected by a christie box. The sampling point should not be located in an area where water from irrigation or flow from stormwater runoff can accumulate.


3Ventilation

3.1Regulations, Standards and References

Regulations:

  • California Code of Regulations (CCR), Title 8, Section 5154.1, Ventilation requirements for laboratory type hood operations
  • California Code of Regulations, Title 8, Section 5209, Carcinogens
  • Carcinogens Code of Federal Regulation (CFR) 10, Parts 20 and 35
  • National Fire Protection Association (NFPA) Handbook 45, Standard on Fire Protection for Laboratories Using Chemicals
  • National Fire Protection Association (NFPA) Handbook 99 Standard for Health Care Facilities

Consensus Standards and References:

  • American National Standards Institute (ANSI), Z358.1 Emergency Eyewash and Shower Equipment
  • American National Standard for Laboratory Ventilation (ANSI/AIHA Z9.5)
  • American National Standard for Thermal Environmental Conditions for Human Occupancy (ANSI/ASHRAE 55-1992)
  • The CalDAG – California Disabled Accessibility Guidebook
  • Guide for the Preparation of Applications for Medical Programs (RH 2010 4/90) (not formally adopted) (DOHS 2010)
  • “CRC Handbook of Laboratory Safety, 4th Ed.” CRC Press 1995.
  • “Safe Handling of Radionuclides”, International Atomic Energy Agency, Safety Series No. 1, (1973 ed. is still current as of 1999) (IAEA)

3.2Scope

The requirements of this Guide applies to all Stanford laboratory buildings, laboratory units, and laboratory work areas in which hazardous materials are used, handled, or stored.

3.3General Ventilation Considerations

1. The room should have mechanically generated supply air and exhaust air. All lab rooms shall use 100% outside air and exhaust to the outside. There shall be no return of fume hood and laboratory exhaust back into the building.

Good Practice per Stanford University EH&S

Prudent Practices in the Laboratory 8.C, 8.D

CCR, Title 24, Part 3, Section 505.3

NFPA 45, Chapter 6-4.1

ANSI/AIHA Z9.5, 4.10.3 

The air balance of the room cannot be adjusted unless there is mechanically generated supply and exhaust air. 

2.  Mechanical climate control should be provided.

Good Practice per Stanford University EH&S 

  • Per ASHRAE 55-1992, comfortable temperature range are defined as follows: Winter: 69-76 °F (at 35% RH); Summer: 73-79 °F (at 60% RH)
  • Electrical appliances often exhaust heat into a room (e.g., REVCO freezer, incubator, and autoclave). Failure to take this effect into consideration may result in an artificially warm working environment. Windows must not be opened for a cooling effect since the room air balance will be altered. A cool room must not be heated with a portable heater that may be a fire hazard.

3. Cabinetry or other structures or equipment must not block or reduce effectiveness of supply or exhaust air.

Good Practice per Stanford University EH&S

Many supply diffusers and room exhaust room outlets are located along laboratory walls. Storage of boxes near these openings may obstruct the circulation of air and supply or exhaust air functioning.

4.  Ventilation Rates

  • General laboratories using hazardous materials shall have a minimum of 6 air changes per hour (ACH). Exhaust ventilation shall be continuous.

2013 CMC section 403.7, Table 403.7

2013 California Fire Code 5004.3

2015 ASHRAE Handbook—HVAC Applications, Chapter 16

The Fire Code requires exhaust ventilation at 1 cfm/ft2 of floor area for dispensing, use, and storage of hazardous materials in buildings operating above the maximum allowable quantity (MAQ). In a room with a 10 ft. ceiling, this equates to 6 ACH. The Mechanical Code requires a minimum exhaust ventilation rate of 1 cfm/ft2 for Educational Science Laboratories.

  • Upon consultation with EH&S, some labs may be candidates for reduced airflow changes (from 6 ACH to 4 ACH) when unoccupied during nonbusiness hours.
  • Many laboratory buildings now have laser rooms and rooms with analytic tools that do not require hazardous materials. Such rooms have been permitted with 3 to 4 ACH. Careful consideration should be given to not only current, but also future use of the laboratory as research needs change. Without adequate exhaust ventilation, future use of hazardous materials in the space will be restricted or require potentially costly retrofitting.

5.  Laboratories must be maintained under negative pressure in relation to the corridor or other less hazardous areas. Clean rooms requiring positive pressure should have entry vestibules provided with door-closing mechanisms so that both doors are not open at the same time. Consult with SU Fire Marshal for design details. 

ANSI/AIHA Z9.5 – 1992, 4.11.4-4.11.5

As a general rule, airflow should be from areas of low hazard, unless the laboratory is used as a clean or sterile room.

6.  Where appropriate, general ventilation systems should be designed, such that, in the event of an accident, they can be shut down and isolated to contain radioactivity.

Good Practice per Stanford University 

7.  The air velocity volume in each duct should be sufficient to prevent condensation or liquid or condensable solids on the walls of the ducts.

Good Practice per Stanford University

The ACGIH Industrial Ventilation handbook (22nd edition) recommends a velocity of 1000- 2000 fpm.

8.  Fume hoods should not be the sole means of room air exhaust. General room exhaust outlets shall be provided where necessary to maintain minimum air change rates and temperature control.

Good Practice per Stanford University 

9.  Operable windows should be prohibited in new lab buildings and should not be used on modifications to existing buildings.

Good Practice per Stanford University

10.  Local exhaust ventilation (e.g., “snorkels” or “elephant trunks”), other than fume hoods, shall be designed to adequately control exposures to hazardous chemicals. An exhausted manifold or manifolds with connections to local exhaust may be provided as needed to collect potentially hazardous exhausts from gas chromatographs, vacuum pumps, excimer lasers, or other equipment which can produce potentially hazardous air pollutants. The contaminant source needs to be enclosed as much as possible, consistent with operational needs, to maximize control effectiveness and minimize air handling difficulties and costs.

ACGIH, Industrial Ventilation: A Manual of Recommended Practice, 23rd edition, or latest edition

Enclosure minimizes the volume of airflow needed to attain any desired degree of containment control. This reduces fan size, motor horsepower, make up air volume, and make up air conditioning costs.

11.  Hoods should be labeled to show which fan or ventilation system they are connected to.

Good Practice per Stanford University 

12.  No laboratory ventilation system ductwork shall be internally insulated. Sounds baffles or external acoustical insulation at the source should be used for noise control. 

Good Practice per Stanford University

Fiberglass duct liner deteriorates with aging and sheds into the space resulting in IAQ complaints, adverse health effects, maintenance problems and significant economical impact. Glass wool and refractory ceramic fibers are now rated as possible carcinogens by the National Toxicology program.

13.  Air exhausted from laboratory work areas shall not pass unducted through other areas.

NFPA 45, Chapter 6-4.3

3.4Negative Pressurization

1. Airflow shall be from low hazard to high hazard areas.

Good Practice

CDC-NIH Biosafety in Microbiological and Biomedical Laboratories

Prudent Practices in the Laboratory 8.C, 8.D

NFPA 45,6.4.4

Anterooms may be necessary for certain applications, such as clean rooms or tissue culture rooms. Potentially harmful aerosols can escape from the containment of the laboratory room unless the room air pressure is negative to adjacent non-laboratory areas.

It is recommended that laboratories should contain a fully integrated laboratory control system to control the temperature, ventilation rate and room pressurization. The control system should constantly monitor the amount of supply and exhaust air for the laboratory rooms and regulate the flow to maintain a net negative pressurization.

2. An adequate supply of make up air (90% of exhaust) should be provided to the lab.

Good Practice per Stanford University

3. An air lock or vestibule may be necessary in certain high-hazard laboratories to minimize the volume of supply air required for negative pressurization control. These doors should be provided with interlocks so that both doors cannot open at the same time.

Good Practice per Stanford University

4. A corridor should not be used as a plenum.

Good Practice per Stanford University

3.5Supply Air Arrangements

1.  Room air currents at the fume hood should not exceed 20% of the average face velocity to ensure fume hood containment.

Prudent Practices in the Laboratory 8.C

Good Practice per Stanford University

ANSI Z9.5-2003

Z9.5-2003 allows air velocities up to 50 fpm, but lower room air velocities around hoods cause less interference with the operation of the hood. Make up air should be injected at low velocity through an opening with large dimensions to avoid creating jets of airflow. An alternative is to direct air towards a ceiling that will allow the air velocity to decrease by the time it approaches a hood.

2.  Make-up air should be introduced at opposite end of the laboratory room from the fume hood(s) and flow paths for room HVAC systems shall be kept away from hood locations, to the extent practical.

NFPA 99, Chapter 5-4.3.2

NFPA 45, Chapter 6-3.4 and 6-9.1

NIH Design Policy and Guidelines, Research Laboratory, 1996, D.7.7

ANSI Z9.5-2003

Air turbulence defeats the capability of hoods to contain and exhaust contaminated air.

3.  Make-up air shall be introduced in such a way that negative pressurization is maintained in all laboratory spaces and does not create a disruptive air pattern.

Good Practice per Stanford University

4.  Cabinetry or other structures or equipment should not block or reduce effectiveness of supply or exhaust air.

Good Practice per Stanford University 

5.  Supply system air should meet the technical requirements of the laboratory work and the requirements of the latest version of ASHRAE, Standard 62, Ventilation for Acceptable Indoor Air Quality.

Good Practice per Stanford University

3.6Fume Hood Location

1.  Fume hoods should be located away from activities or facilities, which produce air currents or turbulence. Locate away from high traffic areas, air supply diffusers, doors, and operable windows.

NFPA 99, Chapter 5-4.3.2

NFPA 45, Chapter 6-3.4 and 6-9.1 

Air turbulence affects the capability of hoods to exhaust contaminated air. Eddies are created by people passing by and by other sources of air currents.

2.  Fume hoods should not be located adjacent to a single means of access to an exit. Recommend that hoods be located more than 10 feet from any door or doorway.

NFPA 45, Chapter 6-9.2

NFPA 45, Chapter 3-4.1(d)

NFPA 99, Chapter 5-4.3.2

ANSI/AIHA Z9.5, 5.4 

A fire hazard or chemical release incident, both of which may start in a fume hood, can block an exit rendering it impassable. A fire or explosion in a fume hood located adjacent to a path of egress could trap someone in the lab.

3.  Fume hood openings should not be located opposite workstations where personnel will spend much of their working day, such as desks or microscope benches.

NFPA 45, Chapter 6-9.3

Materials splattered or forced out of a hood could injure a person seated across from the hood.

4.  An emergency eyewash/shower station shall be within 10 seconds of each fume hood.

CCR, Title 8, Section 5162

ANSI Z358.1

Per 8 CCR 5162, the requirement for an eyewash/shower is triggered when an employee may be exposed to substances, which are “corrosive or severely irritating to the skin or which are toxic by skin absorption” during normal operations or foreseeable emergencies. Fume hoods are assumed to contain such substances; hence, Stanford interprets this regulation to mean that emergency eyewash/shower station shall be within 10 seconds of fume hoods.

5.  An ADA emergency eyewash/shower shall be within 10 seconds of an ADA fume hood (minimally one ADA hood per laboratory floor).

The CalDAG – California Disabled Accessibility Guidebook

The location of at least one ADA hood per floor will enable disabled individuals to conduct their research without having to transport chemicals, etc. in elevators.

3.7Approved Equipment

1.  All fume hoods shall meet the requirements of CCR, Title 8, Sections 5141.1, 5209, and 5143 in addition to NFPA 45, Standard on Fire Protection For Laboratories Using Chemicals.

3.8Fume Hood and Local Exhaust Ventilation Selection/Types

1.  General: Factors to consider when selecting a fume hood:

  • Room size (length x width x height)
  • Number of room air changes
  • Lab heat load
  • Types of materials used
  • Linear feet of hood needed based on
  1. number of users/hood
  2. frequency of use
  3. % of time working at hood
  4. size of apparatus to be used in hood, etc.

A facility designed for intensive chemical use should have at least 2.5 linear feet of hood space per student.

Good Practice per Stanford EH&S

Evaluating the operational and research needs of the users will ensure that the appropriate type and number of hoods are integrated into the laboratory.

2.  Constant Volume Hoods

These hoods permit a stable air balance between the ventilation systems and exhaust by incorporating a bypass feature. If bypass is 100% this allows a constant volume of air to be exhausted through the hood regardless of sash position.

3.  Variable Air Volume (VAV) fume hoods

These hoods maintain constant face velocities by varying exhaust volumes in response to changes in sash position. Because only the amount of air needed to maintain the specified face velocity is pulled from the room, significant energy savings are possible when the sash is closed. However, since these hoods cost more than up front and more maintenance, effective sash management (e.g., pull sash closed when not using hood) is necessary.

4.  Supply or auxiliary air hoods

These hoods are not permitted, unless an exception is granted by EH&S.

Good Practice per Stanford University EH&S

It is very difficult to keep the air supply and exhaust of supply hoods properly balanced. In addition, the supply air is intemperate, causing discomfort for those working in the hot or cold air stream. As a result, the supply vent is often either shut or blocked off, which eliminates any potential benefit of this type of hood. Finally, the presence and movement of the user’s body in the stream of supply air creates turbulence that degrades the performance of the hood.

5.  Ductless Fume Hoods: Portable, non-ducted fume hoods are generally not permitted; however, a portable hood may be used for limited applications (e.g., used inside of an existing hood for a special application, such as odor control). Such applications must be reviewed and approved by EH&S on a case-by-case basis.

ANSI/AIHA Z9.5, 5.16

Portable hoods often do not meet the regulatory airflow requirements. Filters used with these units must be changed frequently and vary in filtration effectiveness from chemical to chemical. Experience has demonstrated that an OSHA compliance officer may require quarterly monitoring of hood exhaust to demonstrate the effectiveness of the filtration in the given application and the corresponding protection of the workers occupying the space. These hoods are often misused.

6.  Perchloric/Hot Acid Hoods: 

a)  Heated perchloric acid shall only be used in a laboratory hood specifically designed for its use and identified as “For Perchloric Acid Operations.” (Exception: Hoods not specifically designed for use with perchloric acid shall be permitted to be used where the vapors are trapped and scrubbed before they are released into the hood.)

NFPA 45, Chapter 6-11.1

Heated perchloric acid will give off vapors that can condense and form explosive perchlorates. Limited quantities of perchloric acid vapor can be kept from condensing in laboratory exhaust systems by trapping or scrubbing the vapors at the point of origin.

b) Perchloric acid hoods and exhaust duct work shall be constructed of materials that are acid resistant, nonreactive, and impervious to perchloric acid. 

8 CCR 5154.1(e)(7)

NFPA 45, Chapter 6-11.2

ANSI/AIHA Z9.5 

c) The exhaust fan should be acid resistant and spark-resistant. The exhaust fan motor should not be located within the duct work. Drive belts should not be located within the duct work.

NFPA 45, Chapter 6-11.3 

d)  Ductwork for perchloric acid hoods and exhaust systems shall take the shortest and straightest path to the outside of the building and shall not be manifolded with other exhaust systems. Horizontal runs shall be as short as possible, with no sharp turns or bends. The duct work shall provide a positive drainage slope back into the hood. Duct shall consist of sealed sections. Flexible connectors shall not be used.

NFPA, Chapter 6-11.4

e)  Sealants, gaskets, and lubricants used with perchloric acid hoods, duct work, and exhaust systems shall be acid resistant and nonreactive with perchloric acid.

NFPA 45, Chapter 6-11.5

ANSI/AIHA Z9.5

f)  A water spray system shall be provided for washing down the hood interior behind the baffle and the entire exhaust system. The hood work surface shall be watertight with a minimum depression of 13 mm (1⁄2 inch) at the front and sides. An integral trough shall be provided at the rear of the hood to collect wash-down water.

8 CCR 5154.1(e)(7)

NFPA 45, Chapter 6-11.6

ANSI/AIHA Z9.5

Perchloric acid is a widely used reagent know to produce flammable or explosive reaction products; hence, the need to have wash down capabilities after each use to remove residues. A watertight surface will contain any chemical spills or leaks from leaking to underneath hood.

g) Spray wash-down nozzles shall be installed in the ducts no more than 5 ft. apart. The ductwork shall provide a positive drainage slope back into the hood. Ductwork shall consist of sealed sections, and no flexible connectors shall be used.

NFPA 45, Chapter 6-11.4

h) The hood surface should have an all-welded construction and have accessible rounded corners for cleaning ease.

Good Practice per Stanford University EH&S

Access for cleaning is an important design feature.

i) The hood baffle shall be removable for inspection and cleaning.

NFPA 45, Chapter 6-11.7

j) Each perchloric acid hood must have an individually designated duct and exhaust system.

ANSI/AIHA Z9.5 

7.  Radioactive Material Use

a)  Laboratory hoods in which radioactive materials are handled shall be identified with the radiation hazard symbol.

NFPA, Chapter A-6-12.1

b)  Fume hoods intended for use with radioactive isotopes must be constructed of stainless steel or other materials that will not be corroded by the chemicals used in the hood.

NCRP Report # 8

NFPA 99, Chapter 5-4.3.3

DOHS2010

CRC Handbook of Laboratory Safety, 4th Ed.

c)  The interior of all radioisotope hoods must have coved corners to facilitate decontamination.

NFPA 99, Chapter 5-4.3.3

DOHS2010

CRC Handbook of Laboratory Safety, 4th Ed.

IAEA, Safe Handling of Radionuclides

Cracks and crevices are difficult to decontaminate.

d) The hood exhaust may require filtration by HEPA or Charcoal HEPA filters. Where such is the likelihood, the hood must have a bag-out plenum for mounting such filters and fan capacity for proper operation of the hood with the filter installed. The most appropriate location for the plenum is near the exhaust port of the fume hood (i.e., proximal to the hood).

NFPA 99, Chapter 5-4.3.3

DOHS2010

CRC Handbook of Laboratory Safety, 4th Ed.

IAEA, Safe Handling of Radionuclides

e) Hoods used for radioactivity should have sashes with horizontal sliding glass panels mounted in a vertical sash. 

NFPA 99, Chapter 5-4.3.3

DOHS2010

10 CFR 20

CRC Handbook of Laboratory Safety, 4th Ed.

IAEA, Safe Handling of Radionuclides 

f) The cabinet on which the hood is installed shall be adequate to support shielding for the radioactive materials to be used therein.

NFPA 99, Chapter 5-4.3.3

DOHS2010

10 CFR 20

CRC Handbook of Laboratory Safety, 4th Ed.

IAEA, Safe Handling of Radionuclides

g) In general, glove boxes with HEPA filtered exhausts shall be provided for operations involving unsealed radioactive material that emit alpha particles. Consult with the Radiation Safety Program for specific requirements.

NFPA 99, Chapter 5-4.3.3

DOHS2010

10 CFR 20

CRC Handbook of Laboratory Safety, 4th Ed.

IAEA, Safe Handling of Radionuclides

8.  American with Disabilities Act (ADA) Hoods: Must consult with Stanford University’s ADA Compliance Office regarding the number lab hoods to install in facilities, which are accessible to and usable by individuals with disabilities – recommend minimally one ADA hood per laboratory floor. These hoods must provide appropriate worksurface heights, knee clearances, reach to controls, etc. to individuals in wheelchairs.

The CalDAG – California Disabled Accessibility Guidebook

The location of at least one ADA hood per floor will enable disabled individuals to conduct their research without having to transport chemicals, etc. in elevators.

9.  Glove Boxes: Glove boxes (positive and negative) must meet the type, design and construction of requirements ANSI/AIHA Z9.5-1992, 5.14.

ANSI/AIHA Z9.5

10.  Walk-in Fume Hoods: These hoods must meet the type, design and construction requirements of ANSI/AIHA Z9.5-1992, 5.13.

ANSI/AIHA Z9.5

11.  Special Purpose Hoods: These hoods include enclosures for operations for which other types of hoods are not suitable (e.g., enclosures for analytical balances, histology processing machines, special mixing stations, evaporation racks). These hoods must be designed per ANSI Z9.2 and the Industrial Ventilation manual.

ANSI/AIHA Z9.5

Industrial Ventilation – A Manual of Recommended Practice (ACGIH)

3.9Fume Hood Labeling

1.  Laboratory hoods and special local exhaust ventilation systems (SLEV) shall be labeled to indicate intended use (e.g., “Perchloric Acid Hood”).

NFPA 45, Chapter 6-12.1

2.  A label must be affixed to each hood containing the following information from the last inspection:

a.  certification date due

b.  average face velocity

c.  inspector’s initials

NFPA 45, Chapter 6-12.2 {NOTE: This code sites slightly different information for the label. Stanford determined it was appropriate to create a label with the above information.}

3.10Fume Hood Construction, Installation & Performance

1.  New hoods can be mounted above a chemical storage cabinet, provided that the cabinet meets the Uniform Fire Code requirements for construction.

Good Practice per Stanford University EH&S

Recommend that solvent storage not be located under the laboratory fume hood, as this location is where fires are most likely to occur in laboratories.

2.  Type 316 stainless steel should be used for all parts of the fume hood system ventilation duct as long as compatibility is maintained.

Good Practice per Stanford University EH&S

This material affords good, general corrosion, impact and vibration resistance.

3.  Fume hood interior surfaces shall be constructed of corrosion resistant, non-porous, non-combustible materials such as type 316 stainless steel, and should be smooth and impermeable, with rounded corners. These materials shall have a flame spread index of 25 or less when tested in accordance with NFPA method 255, Standard Method of Test of Surface Burning Characteristics of Building Materials. 

NFPA 45, Chapter 6-8.1.1, 6-11.2, 6-11.6

NFPA 99, 5-4.3.3

ANSI/AIHA Z9.5-1992, 5.12

Type 316 stainless steel (SS 316) is specified to avoid corrosion, thereby extending fume hood life. Splashes of liquid containing radioactive materials can be easily cleaned when hoods are constructed of non-porous materials such as stainless steel. Perchloric acid digestion over time may result in the condensation and consequential formation of perchlorate crystals, which in large quantities pose an explosion hazard, especially if combined with organic chemical condensate.

4.  Hood inserts are only permitted for radioactive iodination procedures specifically approved by the Stanford Radiation Safety Officer. 

5.  Laboratory hoods shall be provided with a means of containing minor spills.

NFPA 45, Chapter 6-9.1.3

ANSI/AIHA Z9.5, 5.2

The means of containing minor spills might consist of a 6.4-mm (1⁄4 in.) recess in the work surface, use of pans or trays, or creation of a recess by installing a curb across the front of the hood and sealing the joints between the work surface and the sides, back, and curb of the hood.

6.  There must be a horizontal bottom airfoil inlet at the front of the hood.

ANSI/AIHA Z9.5, 5.2

The air foil at the front of the hood floor assures a good sweep of air across the working surface toward the back of the hood. This minimizes the generation of turbulents or eddy currents at the entrance to the hood.

7.  Adjustable baffles with horizontal slots must be present in the fume hood interior at the back and top.

ANSI/AIHA Z9.5, 5.2

Locating the slots in this manner will attain reasonably uniform face velocity under different conditions of hood use as related to heat sources, size, and configuration of equipment in hood.

8.  Before a new fume hood is put into operation, an adequate supply of make up air must be provided to the lab.

Good Practice per Stanford University EH&S  

A fume hood exhausts a substantial amount of air. For this reason, additional make up air must be brought into the room to maintain a proper air balance.

9.  Face Velocity:

Laboratory fume hoods shall provide a minimum average effective face velocity of 100 feet per minute (fpm), with a minimum of 70 fpm at any point.

Ref: 8 CCR 5154.1(c)

10.  Certification: See Stanford University’s laboratory fume hood performance and certification protocol at:

Fume Hood Testing and Performance Standards (LVMP Appendix 10.2.1)

11.  Where the required velocity can be obtained by partly closing the sash, the sash and/or jamb shall be marked to show the maximum opening at which the hood face velocity will meet the requirements.

CCR, Title 8, Section 5154.1(e)(1)

12.  An airflow indicator shall be provided and located so that it is visible from the front of the fume hood.

CCR, Title 8, Section 5154.1(e)(3)

NFPA 45, Chapter 6-8.7.1

ANSI/AIHA Z9.5-1992, 5.8

Follow manufacturer’s procedures for calibration of air flow indicator during installation. Follow manufacturer’s schedule for periodic calibration and maintenance parameters thereafter. Performance criteria for various airflow indicators are as follows:

o Kim Wipes: Shows inward flow.
o Magnahelic Gauges: Mark on gauge inches water read when average face velocity at 100 fpm.
o FPM Readout: Average readout is 100 fpm.
o Audio/Visual Alarms: Go into alarm mode if average face velocity drops to 80 fpm.

13.  Baffles shall be constructed so that they may not be adjusted to restrict the volume of air exhausted through the laboratory hood.

NFPA 45, Chapter 6-8.1.2

14.  Fans should run continuously without local control from hood location and independently of any time clocks. 

Good Practice per Stanford University EH&S

If users have ability to shut off hoods or control their use with a time clock, there is a potential for users to conduct research in a hood that is not operating.

15.  For new installations or modifications of existing installations, controls for laboratory hood services (eg., gas, air, and water) should be located external to the hood and within easy reach.

NFPA 45, Chapter 6-8.5.1

16.  Shutoff valves for services, including gas, air, vacuum, and electricity shall be outside of the hood enclosure in a location where they will be readily accessible in the event of fire in the hood. The location of such a shut-off shall be legibly lettered in a related location on the exterior of the hood.

NFPA 99, Chapter 5-4.3.6

17.  Laboratory hoods shall not have an on/off switch located in the laboratory. Exhaust fans shall run continuously without direct local control from laboratories.

Good Practice per Stanford University

18.  Drying ovens shall not be placed under fume hoods.

Good Practice per Stanford University

3.11Fume Hood Power and Electrical

1.  Chemical fume hood exhaust fans should be connected to an emergency power system in the event of a power failure.

Good Practice per Stanford University EH&S

This backup power source will ensure that chemicals continue to be exhausted. EH&S recognizes that it may not be practical to provide emergency power sufficient to maintain fume hood functioning at normal levels but recommends an emergency supply of at least half of the normal airflow.

2.  Emergency power circuits should be available for fan service so that fans will automatically restart upon restoration after a power outage and supply at least half of the normal airflow. 

Good Practice per Stanford University EH&S 

Continual fan service will ensure that hazardous materials are exhausted continually.

3.  Momentary or extended losses of power shall not change or affect any of the control system’s setpoints, calibration settings, or emergency status. After power returns, the system shall continue operation, exactly as before, without the need for any manual intervention. Alarms shall require manual reset, should they indicate a potentially hazardous condition.

4.  Fume hood ventilating controls should be arranged so that shutting off the ventilation of one fume hood will not reduce the exhaust capacity or create an imbalance between exhaust and supply for any other hood connected to the same system.

NFPA 99, Chapter 5-4.3.4

5.  In installations where services and controls are within the hood, additional electrical disconnects shall be located within 15m (50ft) of the hood and shall be accessible and clearly marked. (Exception: If electrical receptacles are located external to the hood, no additional electrical disconnect shall be required).

NFPA 45, Chapter 6-8.4.1

Locating services, controls, and electrical fixtures external to the hood minimizes the potential hazards of corrosion and arcing.

6.  Hood lighting shall be provided by UL-listed fixtures external to the hood or, if located within the hood interior, the fixtures shall meet the requirements of NFPA 70, (National Electrical Code).

NFPA 45, Chapter 3-6

7.  Light fixtures should be of the fluorescent type, and replaceable from outside the hood. Light fixtures must be displaced or covered by a transparent impact resistant vapor tight shield to prevent vapor contact.

Good Practice per Stanford University EH&S

Fluorescent bulbs radiate less heat than conventional bulbs while maintaining a safe and illuminated work area inside the hood.

8.  The valves, electrical outlets and switches for utilities serving hoods should be placed at readily accessible locations outside the hood. All shutoff valves should be clearly labeled. Plumbing (e.g., vacuum lines) should exit the sides of the fume hood and not the bench top.

NFPA 45, Chapter 6-8.5.1

NFPA 99, Chapter 5-4.3.6 (Health Care) 

Good Practice per Stanford University 

3.12Sashes

1.  Hoods shall have transparent movable sashes constructed of shatter-resistance, flame resistant material and capable of closing the entire front face.

ANSI/AIHA Z9.5-2003,

8 CCR 5154.1(c)

Good Practice per Stanford University

2.  Vertical-rising sashes are preferred. If horizontal sashes are used, sash panels (horizontal sliding) must be 12 to 14 inches in width.

Good Practice per Stanford University

Sashes may offer extra protection to lab workers since they can be positioned to act as a shield.

3.  A force of five pounds shall be sufficient to move vertically and/or horizontally moving doors and sashes.

ANSI/AIHA Z9.5-2003, 3.1.1

3.13Ducting

1.  Hood exhausts should be manifolded together except for: 

  • Perchloric/hot acid hoods
  • hoods with washdown equipment
  • hoods that could deposit highly hazardous residues on the ductwork
  • exhaust requiring HEPA filtration or other special air cleaning
  • situations where the mixing of exhausted materials may result in a fire, explosion, or chemical reaction hazard in the duct system

Manifolded fume hood exhaust ducts shall be joined inside a fire rated shaft or mechanical room, or outside of the building at the roofline.

CCR, Title 8, Section 5143

NFPA 45 

​​2.  Horizontal ducts must slope at least 1 inch per 10 feet downward in direction of airflow to a suitable drain or sump. 

ANSI/AIHA Z9.5-1992, 6.1

Liquid pools and residue buildup which can result from condensation may create a hazardous condition if allowed to collect.

3.  Ducts exhausting air from fume hoods should be constructed entirely of non- combustible material. Gaskets should be resistant to degradation by the chemicals involved and fire resistant.

NFPA 45, Chapter 6-5.1 

4.  Automatic fire dampers shall not be used in laboratory hood exhaust systems. Fire detection and alarm systems shall not be interlocked to automatically shut down laboratory hood exhaust fans.

NFPA 45, Chapter 6-10

Fire dampers are not allowed in hood exhaust ducts. Normal or accidental closing of a damper may cause an explosion or impede the exhausting of toxic, flammable, or combustible materials in the event of a fire.

3.14Exhaust

1. New exhaust fans should be oriented in an up-blast orientation.

Good Practice per Stanford University EH&S

Any other type of fan orientation increases the fan work load and increases the risk of exhaust emission re-entrainment.

2.  Hood exhaust stacks shall extend at least 7 feet above the roof. Discharge shall be directed vertically upward.

CCR, Title 8, Section 5154.1(e)(4)(D)

If parapet walls are present, EHS recommends that stacks extend at least 2 feet above the top of a parapet wall or at least 7 feet above the roof, whichever is greater.

Note: The University Architect/Planning Office must be contacted if any building feature, such as exhaust stacks, extend above the roofline.

3.  Hood exhausts shall be located on the roof as far away from air intakes as possible to preclude re-circulation of laboratory hood emissions within a building. For toxic gas applications, the separation distance shall be at least 75 feet from any intake. 

CCR, Title 8; Section 5154.1(e)(4)

SCCo Toxic Gas Ordinance No. NS-517.44

As future gas necessities are difficult to predict, EH&S recommends at least 75 feet for all applications.

4.  Discharge from exhaust stacks must have a velocity of at least 3,000 fpm. Achieving this velocity should not be done by the installation of a cone type reducer. The duct may be reduced, but the duct beyond the reduction should be of sufficient length to allow the air movement to return to a linear pattern.

ANSI Z..95-2003, 5.3.5

Good Practice per Stanford University EH&S

Strobic-type exhaust fans may be used to address exhaust velocity needs.

5.  Rain caps that divert the exhaust toward the roof are prohibited. 

CCR, Title 8; Section 5154.1(e)(4)

6.  Fume hood exhaust is not required to be treated (e.g., filtered or scrubbed) except…

when one of the following substances is used with a content greater than the percent specified by weight or volume: 

Chemical CAS Reg # Percent
2-Acetylaminofluorene 53936 1.0
4-Aminodiphenyl 92671 0.1
Benzidine (and its salts) 92875 0.1
3,3′-Dichlorobenzidine 91941 1.0
4-Dimethylaminoazobenzene 60117 1.0
alpha-Naphthylamine 134327 1.0
beta-Naphthylamine 91598 0.1
4-Nitrobiphenyl 92933 0.1
N-Nitrosodimethylamine 62759 1.0
beta-Propiolactone 57578 1.0
bis-Chloromethyl ether 542881 0.1
Methyl chloromethyl ether 107302 0.1
Ethyleneimine 151564 1.0

CCR, Title 8, Section 5209(b)11

1,2-Dibromo-3-Chloropropane

Asbestos

Vinyl Chloride

Acrylonitrile

Inorganic Arsenic

Ethylene Dibromide

Ethylene Oxide

Methylene Chloride

Good Practice 

or when used for radioisotope work. In this instance, the fume hood exhaust treatment system must be approved by the SU Radiation Safety Officer prior to installation and use.

7.  Laboratory ventilation exhaust fans shall be spark-proof and constructed of materials or coated with corrosion resistant materials for the chemicals being transported. V-belt drives shall be conductive.

NFPA 45

8.  Vibration isolators shall be used to mount fans. Flexible connection sections to ductwork, such as neoprene coated glass fiber cloth, shall be used between the fan and its intake duct when such material is compatible with hood chemical use factors.

Good Practice per Stanford University 

9.  Each exhaust fan assembly shall be individually matched (cfm, static pressure, brake horsepower, etc.) to each laboratory ventilation system.

Industrial Ventilation Manual 

10.  Exhaust fans shall be located outside the building at the point of final discharge. Each fan shall be the last element of the system so that the ductwork through the building is under negative pressure.

8 CCR 5154.1(e)(6)

ANSI/AIHA Z9.5,

An exhaust fan located other than at the final discharge point can pressurize the duct with contaminated air. Fume hood ducts must be maintained under negative pressure.

11.  Fans shall be installed so they are readily accessible for maintenance and inspection without entering the plenum. If exhaust fans are located inside a penthouse, PPE needs for maintenance workers shall be considered.

NFPA 45

3.15Wind Engineering

1.  Wind engineering evaluations should be conducted for all wind directions striking all walls of a building where fume hood exhaust is likely to have significant ground level impact, or is likely to affect air intake for the same nearby buildings.

Good Practice per Stanford University 

2.  Emergency generator exhaust should be considered in the wind engineering study. 

Good Practice per Stanford University

3.16Noise

1.  System design must provide for control of exhaust system noise (combination of fan-generated noise and air-generated noise) in the laboratory. Systems must be designed to achieve an acceptable Sound Pressure Level (SPL) frequency spectrum (room criterion) as described in the 1991 HVAC Applications Handbook.

ANSI/AIHA Z9.5, 10

1991 HVAC Applications Handbook

 

Acceptable SPL may vary depending on the intended room use. A Noise Criteria (NC) curve of 55 dBA is generally adequate for a standard laboratory.

3.17Specialty, Controlled Climate, And Cold Rooms

1.  The issue of ventilation in cold rooms during periods of occupancy or for storage of hazardous materials must be addressed. EH&S should be consulted to review arrangements for providing fresh and exhaust air during periods of occupancy and for storage of hazardous materials or compressed gases.

Good Practice per Stanford University

Cold Rooms used only for the storage of non-hazardous materials do not require ventilation in addition to that specified by the manufacturer.

2.  Specialty rooms, designed for human occupancy must have latches that can be operated from the inside to allow for escape.

Good Practice per Stanford University

3.  Latches and frames shall be designed to allow actuation under all design conditions, such as freezing. Magnetic latches are recommended.

Good Practice per Stanford University

4.  Doors of walk-in specialty rooms must have viewing windows and external light switches. 

Good Practice per Stanford University

3.18Lab Hood Commissioning

1.  Proper operation of fume hoods must be demonstrated by the contractor installing the fume hood prior to project closeout. The recommended containment performance test is ANSI/ASHRAE 110.

ANSI/AIHA Z9.5-2003, 6.3.7

See certification requirements, Section 3.10, #10. 


4Emergency Eyewash And Safety Shower Equipment

4.1Regulations, Consensus Standards, And References

1.  Regulations

California Code of Regulations (CCR), Title 8, General Industry Safety Orders

  • Section 3273, Working Area
  • Section 5162, Emergency Eyewash and Shower Equipment
  • Section 5217(i), Formaldehyde, Hygiene Protection

CCR, Title 24, Part 5, 2013 California Plumbing Code (CPC)

  • Section 416.0, Emergency Eyewash and Shower Equipment

Palo Alto Municipal Code, Title 16, Chapter 16.09, Sewer Use Ordinance

  • Section 16.09.175, General Prohibitions and Practices

2.  Consensus Standards and References

American National Standards Institute (ANSI), Z358.1-2014, Emergency Eyewash and Shower Equipment

ASTM International, ASTM F1637-13, Standard Practice for Safe Walking Surfaces

National Electrical Code (NEC)

3.  References

Guidelines for Laboratory Design: Health, Safety, and Environmental Considerations, Fourth Edition,Louis J DiBerardinis, Janet S. Baum, Melvin W. First, Gari T Gatwood, and Anand K. Seth, John Wiley & Sons, Inc., Hoboken, New Jersey, 2013.

Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards, Updated Version, The National Academies Press, Washington, D.C., 2011.

Markenson D, Ferguson JD, Chameides L, Cassan P, Chung K-L, Epstein J, Gonzales L, Herrington RA, Pellegrino JL, Ratcliff N, Singer A. Part 17: first aid: 2010 American Heart Association and American Red Cross Guidelines for First Aid. Circulation. 2010;122(suppl 3):S934 –S946.

4.2Scope

This section presents the minimum requirements for eyewash and shower equipment for the emergency treatment of the eyes or body of a person exposed to hazardous substances. It covers the following types of equipment: emergency showers, eyewash and eye/facewash equipment, and combination shower and eyewash or eye/face wash.

4.3Application

1.  Provisions for Emergency Eyewashes

Emergency plumbed eyewash or eye/facewash equipment shall be provided for all work areas where, during routine operations or foreseeable emergencies, the eyes of an employee may come into contact with a substance which can cause corrosion, severe irritation, or permanent tissue damage or is toxic by absorption (see box below). A plumbed eyewash shall be provided at all work areas where formaldehyde solutions in concentrations greater than or equal to 0.1% are handled.

  • T8 CCR, Section 5162(a)
  • T8 CCR, Section 5217(i)(3)
EH&S considers the following to be substances which can cause corrosion, severe irritation, or permanent tissue damage, or which are toxic by absorption:

a.  Substances classified by the manufacturer or distributor according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) as Category 1 (serious eye damage) or Category 2A (irritant) eye hazards.

b.  Substances identified by the manufacturer or distributor as causing corrosion, severe irritation, or permanent tissue damage to the eyes.

c.  Substances designated by “S” in the skin notation column of Table AC-1 of T8 CCR Section 5155.

d.  Substances identified by the manufacturer or distributor as toxic by skin absorption.

This consideration is based on T8 CCR, Section 5162; OSHA Hazard Classification Guidance for Manufacturers, Importers, and Employers; and T8 CCR, Section 5155.

2.  Provisions for Emergency Showers

A plumbed emergency shower shall be provided for all work areas where, during normal operations or foreseeable emergencies, areas of the body may come into contact with a substance which is corrosive or severely irritating to the skin or which is toxic by skin absorption (see box below). A plumbed emergency shower shall be provided at all work areas where formaldehyde solutions in concentrations greater than or equal to 1% are handled.

  • T8 CCR, Section 5162(b)
  • T8 CCR, Section 5217(i)(2)
EH&S considers the following to be substances which are corrosive or severely irritating to the skin or which are toxic by skin absorption:

a.  Substances classified by the manufacturer or distributor according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) as Category 1 (skin corrosion) or Category 2 (skin irritation) skin hazards.

b.  Substances identified by the manufacturer or distributor as corrosive or severely irritating to the skin.
c. Substances designated by “S” in the skin notation column of Table AC-1 of T8 CCR Section 5155.
d.  Substances identified by the manufacturer or distributor as toxic by skin absorption.

This consideration is based on T8 CCR, Section 5162; OSHA Hazard Classification Guidance for Manufacturers, Importers, and Employers; and T8 CCR, Section 5155.

3.  Stanford EH&S presumes that laboratory fume hoods contain hazardous substances that require emergency eyewash and shower facilities.

4.  Laboratories and laboratory support facilities using and handling hazardous substances will generally require eyewash and safety showers. Biological laboratories using bleach and other chemical disinfectants will generally require eyewash and safety showers. Consult with EH&S for any exceptions or if an evaluation is needed.

5.  For new construction and major renovations, careful consideration should be given to not only current, but also future use of the laboratory as research needs change. Without an emergency eyewash and safety shower, future use of hazardous materials in the space will be restricted or require potentially costly retrofitting.

4.4Location

1.  Emergency eyewash and shower equipment shall be on the same level as the hazard and accessible for immediate use in locations that require no more than 10 seconds for the injured person to reach. The path of travel must be free of obstructions. If both eyewash and shower are needed, they shall be located so that both can be used at the same time by one person.

  •   T8 CCR, Section 5162(c)
  •   2013 CPC, Section 416.4

The average person covers a distance of approximately 55 ft. in 10 seconds when walking at a normal pace. The physical and emotional state of a potential victim (visually impaired, with some level of discomfort/pain, and possibly in a state of panic) should be considered along with the likelihood of personnel in the immediate area to assist. Other potential hazards that may be adjacent to the path of travel that might cause further injury should be considered.

  • ANSI Z358.1-2014, Appendix B5

2.  One intervening door can be present so long as it opens in the same direction of travel as the person attempting to reach the emergency eyewash and shower equipment and the door is equipped with a closing mechanism that cannot be locked to impede access to the equipment (i.e., the door is a panic door). Where the hazard is corrosive, consult with EH&S.

  • Good Practice per Stanford University EH&S
  •  ANSI Z358.1-2014, Appendix B5

4.5Performance Requirements

Emergency eyewash and shower equipment shall meet the requirements of ANSI Z358.1-2014. Control valves for all such equipment shall meet the requirements of ANSI Z358.1-2014.

  •   T8 CCR, Section 5162
  •   ANSI Z358.1-2014

4.6Signage And Visibility

1.  The path of travel shall be clearly identified with signage. Emergency eyewash and shower locations must be identified with a highly visible sign positioned so the sign is visible within the area served by eyewash and shower equipment. The areas around the eyewash or shower must be well lit.

  •   2013 CPC, Section 416.4
  •   ANSI Z358.1-2014, Section 4.5.3
  •   ANSI Z358.1-2014, Section 5.4.3

2.  A large contrasting spot (32” diameter) should be painted on, embedded in, or affixed to the floor directly beneath the shower to indicate its location and the area that must be kept free from any obstruction.

  •   Guidelines for Laboratory Design: Health, Safety, and Environmental Considerations
  •   Good Practice per Stanford University EH&S

4.7Prohibitions Around Equipment

1.  No obstructions shall be located within 16 inches from the center of the spray pattern of the emergency shower facility. Note: The eyewash is not considered an obstruction.

  •   T8 CCR, Section 5162(c)
  •   ANSI Z358.1-2014, Section 4.1.4
  •   2013 CPC, Section 416.1

2.  No electrical apparatus or receptacles (electrical outlets) shall be located within a zone measured 3 feet horizontally and 8 feet vertically of eyewash stations or showers. If a 120-volt outlet or receptacle is present within 6 feet of an eyewash or shower, it shall be equipped with a Ground Fault Circuit Interrupter (GFCI).

  • NEC
  • Good Practice per Stanford University EH&S

This prevents potential electrical hazards posed when the water generated by the activated emergency eyewash/safety shower is in proximity to live electrical equipment.

4.8Water Supply

1.  Emergency eyewash and shower equipment shall not be limited in the water supply flow rates. Flow rate and discharge pattern shall be provided in accordance with ANSI Z358.1-2014.

  • 2013 CPC, Section 416.2

2.  Emergency eyewash and shower equipment shall deliver tepid water (60-100°F). Optimal range is 60-77°F, based on first aid recommendations for thermal burns.

  •   2013 CPC, Section 416.2
  •   ANSI Z358.1-2014
  •   2010 American Heart Association and American Red Cross Guidelines for First Aid

4.9Design For Maintenance And Use

1.  Shut-off valves

The water supply to showers and/or shower/eyewash combination units should be controlled by a ball-type shutoff valve which is visible and accessible to shower testing personnel in the event of leaking or failed shower head valves. If shut off valves are installed in the supply line for maintenance purposes, provisions shall be made to prevent unauthorized shut off.

  •   Good Practice per Stanford EH&S
  •   ANSI Z358.1-2014, Section 6.4.5.

This design will make maintenance easier.

2.  Floor Drains

Where feasible, floor drains should be installed below or near safety showers, with the floor sloped sufficiently to direct water from the shower into the sanitary sewer drain.

  • Good Practice per Stanford EH&S
  • Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards, Updated Version

Floor drains will minimize the potential for excessive flooding, which may damage laboratory facilities and equipment, interrupt laboratory operations, cause a reluctance to use the safety shower or to use it for a sufficient amount of time, and create a slipping hazard. Floor drains will also facilitate required monthly testing.

Any floor drain which may be in service during safety shower use shall be installed with a temporary plug which remains closed except when the shower is in use or protected from spills by a covered sump or berm system.

  • Palo Alto Municipal Code, 16.09.175(a)(3)

The installation of a floor drain, temporary plug, covered sump, or berm shall not project into the walking surface so as to create a tripping hazard. Walkways shall be stable, planar, flush, and even to the extent possible. As a minimum level of care, changes in levels between 1/4 and 1/2 inch (6 and 12 mm) shall be beveled with a slope no greater than 1:2 (rise:run). Changes in levels greater than 1/2 inch shall be transitioned by means of a ramp or stairway that complies wi