Guidance for Sanitization/Disinfection of Researcher-Maintained Animal Equipment
Purpose
To provide guidance to investigators for the cleaning, sanitization and disinfection of non-surgical animal research equipment (treadmills, rotarods, operant chambers, mazes, restraint devices, anesthesia induction chambers, etc.) that are maintained by laboratory personnel.
Definitions
- Cleaning removes physical debris (feces, urine, bedding, dust, etc.), which can be accomplished by using physical methods (wiping, sweeping, vacuuming etc.), water, and/or detergents.
- Sanitization reduces germs to safer levels. This can be accomplished by physical methods such as hot water, steam, dry heat, or chemical methods such as detergents or sanitizing agents. Examples of situations in which sanitization is considered adequate include processing of non-barrier rodent cages and routine floor mopping.
- Disinfection kills a broader range of microorganisms (excluding spores), which can be accomplished by using chemical disinfectants or physical methods. Disinfection is more intensive than sanitization, and is recommended in specific situations requiring strict biosecurity practices, or when the equipment cannot be sanitized using hot water either due to incompatibility of the material or size of the equipment.
Guidance
- Cleaning and sanitizing in a mechanical cage washer using hot water (143o – 180o F) and appropriate detergent is the preferred method for research animal equipment that is not required to be sterile.
- Equipment that cannot be cleaned and sanitized or disinfected in a mechanical cage washer may be hand-washed with hot water (143o – 180o F), along with cleaning agents (soap or detergent), and/or chemical disinfectants. The preferred method is to immerse all items in the cleaning solution or disinfectant, followed by a thorough rinse with water to remove residual chemicals.
- Animal equipment that cannot be immersed may be cleaned and sanitized or disinfected as follows:
- Vacuum or wipe all animal contact surfaces with a clean damp cloth, sponge or paper towel to remove soil, hair, dander, etc. If a vacuum is used it should be HEPA-filtered to minimize exposure to allergens;
and
- Spray, wipe, or mist all animal contact surfaces with an approved disinfectant (see table below), or wipe animal contact surfaces with ready-to-use disposable disinfectant wipes.Disinfectants must be used according to manufacturers’ guidelines to ensure appropriate dilution and contact time for disinfection. Personnel must follow the manufacturer’s safety procedures when using disinfectants
- Vacuum or wipe all animal contact surfaces with a clean damp cloth, sponge or paper towel to remove soil, hair, dander, etc. If a vacuum is used it should be HEPA-filtered to minimize exposure to allergens;
- Animal equipment should be sanitized or disinfected after each day of use at a minimum, or more frequently if the equipment becomes visibly soiled or contaminated. A log should be maintained for each item of equipment to record the date(s) it was used and when it was cleaned. This log should be available for review during IACUC inspections.
- Validation of the effectiveness of each sanitization regimen should be performed, with re-validation at appropriate intervals, and whenever there is a change in the cleaning and disinfection regimen. UCI veterinary staff can advise researchers on this testing. Testing methods may include:
- ATP testing using a luminometer
- Bacterial cultures using RODAC plates (Replicate Organism Detection and Counting)
Disinfectants for Non-surgical Animal Research Equipment in Laboratories
Chemical disinfectants are regulated and tested for efficacy against specific microbes under defined conditions.
Physical methods of disinfection include UV light, dry heat, and moist heat such as autoclaving. Autoclaving and dry heat can also be considered sterilization when properly validated. UV light is limited by surface shadowing, penetration depth, and safety considerations. Moist heat and autoclaving are not suitable for some equipment. For these reasons, chemical disinfectants are a practical choice for most animal equipment. Examples of items for which disinfection is recommended include animal transfer stations, biosafety cabinets, procedure tables, restraint devices, and behavior testing equipment.
General guidance regarding acceptable surface disinfectants for non-surgical animal research equipment are provided in the table below.
You must check information from the manufacturer regarding spectrum of activity (EPA claims), toxicity, contact time, material compatibility and requirements for safety for animals, humans and the environment.
| Disinfectant | Spectrum of Activity | Contact Time | Material Compatibility | Toxicity & Odor | Shelf Life of Working Concentration |
|---|---|---|---|---|---|
| Accelerated Hydrogen Peroxide (AHP) | Broad-spectrum; effective against bacteria, viruses (enveloped & non-enveloped), and spores | 1-5 minutes | Safe for most materials; less corrosive than bleach | Low toxicity; minimal odor; low aversiveness to animals; special procedures for avian areas | 30 days if diluted from concentrate, 3 years for ready to use liquid |
| Alcohols (70% Ethanol, 70% Isopropanol) | Effective against bacteria and enveloped viruses; limited for non-enveloped viruses and spores | Varies depending on agent | Can damage plastics and rubber; evaporates quickly | Flammable; drying; strong odor | Typically 2-3 years if unopened and stored properly |
| Chlorine Dioxide Liquid | Broad-spectrum; effective against bacteria, viruses (enveloped & non-enveloped), and spores | <1 minute | Can be corrosive; requires careful material compatibility assessment | Requires on-site preparation; short shelf-life; respiratory irritation risk | Depends on the formulation, typically 24 hours to 7 days after activation |
| Citric Acid & Silver Ions | Effective against bacteria, viruses (enveloped), and fungi | 5-10 minutes | Safe for use on most materials | Low toxicity; minimal odor; non-irritating | Depends on formulation, check label |
| Peracetic Acid | Broad-spectrum; effective against bacteria, viruses (enveloped & non-enveloped), and spores | 5–10 minutes | Corrosive; can degrade metals and plastics | Pungent odor; skin and respiratory irritant; requires proper ventilation | 7 days after dilution from concentrate |
| Sodium Hypochlorite (bleach) | Broad-spectrum; effective against bacteria, viruses (enveloped & non-enveloped), and spores at higher concentrations | 5-6 minutes | Corrosive to metals; can degrade plastics; inactivated by organic matter | Strong odor; mucous membrane irritation; aversive to animals | 24 hours |
| Quaternary Ammonium Compounds (Quats) | Effective against bacteria and enveloped viruses; limited for spores and non-enveloped viruses | 10 minutes | Non-corrosive; safe for most materials | Low toxicity; minimal odor; not typically aversive to animals | Typically several weeks, check label |
Consultations for Specialized Animal Equipment
For guidance about how to clean and sanitize/disinfect specialized or sensitive animal equipment, please consult with the equipment manufacturer’s instructions. If the manufacturer’s recommended procedure differs from the guidance described on this page, email IACUC@uci.edu to discuss the proposed sanitization/disinfection method. All methods must be documented in the approved IACUC protocol.
References:
- Guide for the Care and Use of Laboratory Animals: Eighth Edition. 2011: pp. 70-73
- Animal Welfare Regulations; 9 CFR AWA (5-1-2023 Edition)
- CDC Guidelines for Chemical Disinfectants
- CDC Guidance for Cleaning, Sanitizing, and Disinfection (331782-A)
- Clorox® Dilution table
- Special thanks to Kansas State University for sharing their disinfection guidance (https://www.k-state.edu/comply/iacuc/aop-assurances/guidelines/24.html