How to use this tool
Consult manufacturer directions to determine the efficacy of the disinfectant against the biohazards in your lab and be sure to allow for sufficient contact time. Some disinfectants appropriate for lab use include: household bleach (5-10% solution), quaternary ammonium compounds, and phenolic compounds.
When choosing a disinfectant consider the following:
- The microorganisms present
- The item to be disinfected or surface(s)
- Corrosivity or hazards associated with the chemicals in the disinfectant
- Ease of use
70% Ethanol
Aqueous alcohol solutions are not appropriate for surface decontamination because of the evaporative nature of the solution; a contact time of ten minutes or more is necessary and not achievable using a 70% (v/v) aqueous solution of ethanol. 70% ethanol can be used to soak small pieces of surgical instruments and for wipe downs following a disinfectant (e.g., 10% bleach) that might leave a corrosive residue.
Bleach
Chlorine compounds such as bleach are commonly used in the lab because of the relative ease in accessibility and low cost. Chlorine (hypochlorite) compounds are effective in inactivating vegetative bacteria, fungi, lipid and non-lipid viruses, Coxiella burnetii and TB.
- Chlorine compounds have some effect in inactivating bacterial spores.
- Recommended contact time: 10 minutes
- Recommended Working Dilution: 5000 ppm (1:10 dilution of household bleach, 5% hypochlorite ion)
Recommended for: floors, spills (inactivating liquid specimens), bench tops and contaminated clothing. Undiluted bleach and other disinfectants must not go down the drain.
Difficult organisms
Some agents such as Cryptosporidium, Bacillus spores and prions are very resistant to the usual disinfectants. EHS Biosafety is available to assist you in determining the appropriate disinfectant and provides guidance on use of appropriate disinfection techniques and materials for researchers.
This information was provided to the University of Virginia by:
Barbara Fox Nellis
Johnson & Johnson
Clinical Diagnostics
1999 Lake Avenue
Bldg. 83, KRL
Rochester, NY 14650-2209
phone: (716) 453-5697
fax: (716) 453-5696
Recommended Use
- Cleaning some instruments
- Cleaning skin
How It Works
- Changes protein structure of microorganism
- Presence of water assists with killing action
Advantages
Disadvantages
- 50% Solution not very effective -Not active when organic matter present
- Not active against certain types of viruses
- Evaporates quickly
- Contact time not sufficient for killing
Comments & Hazards
- Flammable
- Eye Irritant
- Toxic
Recommended Use
- Spills of human body fluids
- Bactericidal – Good
- Fungicidal – Good
- Sporicidal – Good at >1000ppm Sodium Hypochlorite
How It Works
- Free available chlorine combines with contents within microorganism reaction byproducts cause its death
- Need 500 to 5000 ppm
- Produce chemical combination with cell substances
- Depends upon release of hypochlorous acid
Advantages
- Kills hardy viruses (e.g. hepatitis)
- Kills a wide range of organisms
- Inexpensive
- Penetrates well
- Relatively quick microbial kill
- May be used on food prep surfaces
Disadvantages
- Corrodes metals such as stainless aluminum
- Organics may reduce activity
- Increase in alkalinity decreases bactericidal property
- Unpleasant taste and odor
- Tuberculocidal with extended contact time
Comments & Hazards
- Follow spill procedure and dilution instructions
- Make fresh solutions before use
- Eye skin and respiratory irritant
- Corrosive
- Toxic
Examples
- Bleach solutions (sodium hypochlorite)
- Clorox
- Cyosan
- Purex
Recommended Use
- Bactericidal – Good
- Fungicidal – Good
- Tuberculocidal – Excellent
- Virucidal – Good
- Sporicidal – Good
How It Works
- Coagulates cellular proteins
Advantages
- Non-staining relatively noncorrosive
- Useable as a sterilant on plastics, rubber, lenses, stainless steel and other items that can’t be autoclaved
Disadvantages
- Not stable in solution
- Has to be in alkaline solution
- Inactivated by organic material
Comments & Hazards
- Eye skin and respiratory irritant
- Sensitizer
- Toxic
Examples
- Calgocide 14
- Cidex
- Vespore
Recommended Use
- Disinfecting some semicritical medical equipment
- Bactericidal – Very Good
- Fungicidal – Excellent
- Virucidal – Excellent
How They Work
- Free iodine enters microorganism and binds with cellular components
- Carrier helps penetrate soil/fat
- Need 30 to 50 ppm
- Probably by disorder of protein synthesis due to hindrance and/or blocking of hydrogen bonding</li>
Advantages
- Kills broad range of organisms
- Highly reactive
- Low tissue toxicity
- Kills immediately rather than by prolonged period of stasis
- Not affected by hard water
- May be used on food prep surfaces
Disadvantages
- May stain plastics or corrode metal
- May stain skin/laundry
- Stains most materials
- Odor
- Some organic and inorganic substances neutralize effect
- Tuberculocidal with extended contact time
- Sporicidal, some
Comments & Hazards
- Dilution critical
- Follow directions!
- Use only EPA registered hard surface iodophor disinfectants
- Don’t confuse skin antiseptic iodophors for disinfectants
- Skin and eye irritant
- Corrosive
- Toxic
Examples
- Bactergen
- Hy-Sine
- Ioprep
- Providone (iodine/betadine)
- Wescodyne
Recommended Use
- Bactericidal – Excellent
- Fungicidal – Excellent
- Tuberculodial – Excellent
- Virucidal – Excellent
How They Work
- Gross protoplasmic poison
- Disrupts cell walls
- Precipitates cell proteins
- Low concentrations inactivate essential enzyme systems
Advantages
- Nonspecific concerning bactericidal and fungicidal action
- When boiling water would cause rusting the presence of phenolic substances produces an antirusting effect
Disadvantages
- Unpleasant odor
- Some areas have disposal restrictions
- Effectiveness reduced by alkaline pH, natural soap or organic material
- Sporicidal, no
Comments & Hazards
- Skin and eye irritant
- Sensitizer
- Corrosive
- Toxic
Examples
- Hil-Phene
- Lph
- Metar
- Vesphene
Recommended Use
- Ordinary housekeeping (e.g. floors, furniture, walls)
- Bactericidal – Excellent
- Fungicidal -Good
- Virucidal – Good (not as effective as phenols)
How They Work
- Affects proteins and cell membrane of microorganism
- Releases nitrogen and phosphorous from cells
Advantages
- Contains a detergent to help loosen soil
- Rapid action
- Colorless, odorless
- Non-toxic, less corrosive
- Highly stable
- May be used on food prep surfaces
Disadvantages
- Does not eliminate spores, TB bacteria, some viruses
- Effectiveness influenced by hard water
- Layer of soap interferes with action
Comments & Hazards
- Select from EPA list of hospital disinfectants
- Skin and eye irritant
- Toxic
Examples
- Coverage 258
- End-Bac
- Hi Tor