Stanford University

Lab Safety

Each laboratory environment poses a unique set of hazards, including chemical, biological, physical, and radiological hazards. The following are general safe laboratory practices for personnel working in labs where hazardous chemicals are used and/or stored. See the Laboratory Chemical Safety Toolkit for more information on laboratory and chemical safety. If you’re looking for information on Toxic Gas, read about it in the Hazardous Materials topic.

Understanding hazards

  • Know the hazards of the chemicals you are working with. Prior to using a chemical with which you are unfamiliar, consult the Safety Data Sheet (SDS) or other appropriate references.
  • Assume that unknown materials are toxic, and that a mixture is more toxic than its most toxic compound.
  • Minimize exposure to all chemicals, regardless of toxicity or their familiarity. Most laboratory chemicals have not been fully characterized with respect to their toxicity. It is prudent to implement procedures that will minimize the likelihood of exposure. Skin contact should always be avoided. Avoid inhalation of chemicals and never “sniff” to test chemicals.

Research Safety Monthly Spotlight Topics


Know the location and proper use of emergency equipment such as safety showers, fire extinguishers, and fire alarms.

Engineering controls

Minimize chemical exposure through consistent and proper use of laboratory fume hoods, glove boxes, or other ventilated enclosures.

Personal protective equipment (PPE)

When working with hazardous materials or physical hazards, wear:

  • Personal protective equipment (PPE), including a lab coat, safety glasses, and disposable nitrile gloves (at minimum). Some hazards require additional PPE. See Personal Protective Equipment for guidance.
  • Appropriate street clothing, which includes long pants (or equivalent) that cover legs and ankles and non-perforated, closed-toe shoes that completely cover the feet.

Working alone and unattended operations

Working alone should be avoided. Working with hazardous materials and equipment always poses risks to researcher health and safety. However, these risks are heightened when working alone because help is not readily available in case of a mishap.

To reduce the risks of working alone:

  • Do not perform tasks that are not appropriate for working alone.
  • Reduce the amount(s) of hazardous materials used.
  • Know the location of, and maintain clear access to, emergency equipment (e.g., safety shower, eye wash, fire extinguisher).
  • Check alarm systems (e.g., oxygen sensors) frequently and immediately take action upon alarm activation.
  • Implement a buddy system.

For a list of tasks that require PI approval for working alone, tips on how to implement a buddy system and additional information on how to work safely, please see the full Working Alone Guidance.

Avoid ingesting chemicals


  • Wash your hands frequently to minimize chemical exposure through ingestion and direct contact with the skin.
  • Always wash hands before eating, drinking, smoking, or applying cosmetics.


  • Use mouth suction for pipetting or siphoning.
  • Consume or store food or beverages or apply cosmetics in laboratories (including refrigerators and cold rooms) or in chemical storage areas.


Label all chemical containers with the identity of the contents. Do not use abbreviations or acronyms. Include hazard warning and chemical concentration information.


Use appropriate safety carriers (secondary containment) when transporting chemicals, either inside or outside of the building.

Lab cleanliness

Keep work areas clean and uncluttered. Clean up work areas on completion of an operation or at the end of the day.

Cold and warm rooms

As most controlled temperature rooms (i.e. cold or warm rooms) lack mechanical exhaust (100% recirculated air), storage and use of toxic substances, flammable solvents, corrosive acids, asphyxiants (such as nitrogen and carbon dioxide), and open flames (e.g. Bunsen burners) is strictly prohibited.

Open Flame Fact Sheets

Bunsen Burner Alternative Products
Open Flames – Safe Practices
Open Flames in Laboratories

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