Kevin Lorcheim Engineer ClorDiSys Solutions, Inc - …labsg.org/lorcheim.pdf · Revision Date: June...

Revision Date: June 22, 2008

Facility Decontamination andQuality Assurance

Kevin LorcheimEngineerClorDiSys Solutions, Inc

Facility Decontamination

Decontaminating the DifficultSince 2001

Decontaminating facilities can be performed for various reasons, including:

• During Facility Commissioning

• After Facility Renovation

• Before Facility Renovation

• Routine Preventative Maintenance

• Between Populations

• During Facility Shutdown

• After an Outbreak

Decontamination of Brand New Facility


Consider your current facility:

• Would you want unfiltered outside air coming in?

• Would you want workers walking in directly from the street?

A brand new facility should be thought of just like an operational facility. While you cannot build a facility under aseptic conditions, it can and should be decontaminated once construction is completed and contamination control measures can be put into place.

Decontamination of Brand New Facility


For brand new facilities, it is important to decontaminate just prior to animals being brought in. This allows the facility to be guaranteed clean, with no outside pathogens or organisms which can harm animals and affect research outcomes.

Equipment can be brought in and put in place prior to decontamination, saving lots of time compared to autoclaving items in.

Decontamination After Renovation


Just like a brand new facility, facilities should also be decontaminated after renovations occur.

Decontaminating an area after a construction crew has completed it’s work ensures that the area is free of pathogens and organisms which can harm the animals re-entering the space.

This also protects the research done, as it guarantees that no outlying issues are present to affect results.

Decontamination Before Renovation


Depending on what an area was being used for, it may be necessary to decontaminate it prior to renovation work being done. Done to ensure that workers performing the renovation will be safe from organisms used within the facility. Also ensures that no organisms are “kicked up” and spread around during renovation work.

For example: A project to renovate a TB lab, or other BSL area where harmful pathogens were used should be decontaminated prior to renovation.

Decontamination Before Renovation


Renovations can be completed by workers in PPE, but this usually involves a specialized crew with much higher labor costs than standard construction crews.

Decontamination Done for Prevention


Usually can’t preventatively decon an entire facility at once as the animals would have to be removed.

Routine decontamination would then entail room by room decon, where the rooms are rotationally emptied (of animals) and then decontaminated.

Decontamination Between Populations


Some facilities decontaminate between research populations / studies. Once a study is complete, and before the next one begins, the facility is decontaminated to again “start fresh” for the incoming study.

Decontamination During Facility Shutdown


Before a facility is closed / repurposed, it is often necessary to decontaminate.

• Facility is moving to another location

• Facility is being repurposed

• Facility had an expiring lease

• Building is being demolished

Much like decontaminating prior to a renovation, it is important to leave the facility safe for people to enter once it is shutdown.

Decontamination After an Outbreak


If there’s a widespread contamination, the entire facility should be decontaminated, including the HVAC system.

No brain necessary to understand this application

“That makes sense!”

Decontamination Methods


There are many decontamination methods which are used in laboratories and vivaria. They range from low-level liquid antiseptics to high-level gaseous sterilants.

Antiseptics and Germicides: Used to prevent infection and decay by inhibiting the growth of microorganisms.

Sanitizers: Used to reduce, but not necessarily eliminate, microorganisms.

Disinfectants: Used on hard inanimate surfaces and objects to destroy or irreversibly inactivate infectious fungi and bacteria but NOT necessarily their spores.

Sterilizers (Sporicides): Used to destroy or eliminate all forms of microbial life including fungi, viruses, and all forms of bacteria and their spores.Spores are considered to be the most difficult form of microorganism to destroy.

Decontamination Methods


Common Decontamination Methods:

• Spray / Wipe / Fogging

• Fumigation

• Vapor Phase Hydrogen Peroxide

• Formaldehyde Gas

• Chlorine Dioxide Gas

Spray and Wipe Method


A person or team of people sprays and wipes a liquid disinfectant or sterilant around, attempting to wet every surface.

Surfaces must be kept wet for a certain length of time, dependent on the product and concentration used.

Spray and Wipe Method


• Pro’s• Low cost• Minimal Equipment• Easy job

• Con’s• Difficult job• Hard to reach all surfaces

• Under side of components

• Behind equipment• Ceilings• Ventilation grills• Intricate components

Fogging Method


A person or team using a high level liquid disinfectant the fogger sprays droplets around the room

• Decontaminating agent must be chosen based on level of decontamination required (germicide, sanitizer, disinfectant, sterilant)

• Requires keeping the surface wet or submersed per EPA approved label requirements

• Foggers create small droplets (5-100 microns)

Fogging Method


• Pro’s• Low cost• Minimal Equipment

• Con’s• Hard to reach all surfaces

• Under side of components

• Behind equipment• Ventilation grills• Intricate components

• Hard to coat surfaces evenly• Gravity affects droplets

Vapor Phase Hydrogen Peroxide


Automated equipment heats up liquid HP to boiling point (+109oC) and injects into room. Vapor starts to condense back to liquid state as it cools below 109oC

Starts to act like mists and fogs• Limits distribution• Creates shadow areas

Non-residue forming, although it can absorb into some plastics and take long time to off gas completely

Most organizations consider it to be non-carcinogenic

Formaldehyde Gas


Generated by heating up paraformaldehyde in hot plate (4500F) to release gas

True Gas (boiling point -19oC) which achieves complete distribution.

Formaldehyde is a residue forming carcinogen, which must be neutralized and manually wiped off surfaces.

Banned from most uses, although still found in many facilities today

Chlorine Dioxide Gas


Generated by converting chlorine gas into chlorine dioxide gas by passing it through sodium chlorite.

True Gas (boiling point 51oF) which achieves complete distribution throughout a space.

Non-residue forming

Non-carcinogenicBanned from most uses, although still found in many facilities today

Decontamination Method Overview


Any decontamination method can work provided it achieves the following:

• Complete distribution• Can’t kill if it doesn’t reach it

• Cracks / Crevices• Under and Behind Objects

• Correct concentration for the proper contact time• Dilution and breakdown can be a

problem

Quality Assurance


Quality assurance when dealing with contamination control can involve the test methods in place to monitor for contamination as well as the methods used to ensure the success of a decontamination method.

Monitoring for Contamination Monitoring for DecontaminationSentinals Swab SamplingSwab Sampling Biological IndicatorsATP Monitoring

Sentinels


Sentinel animals are dedicated pathogen free (SPF) animals exposed to soiled bedding from the colony and screened to check for infections within the colony. Sentinels are usually screened once per quarter, with testing results returning a few weeks after.

While testing is very effective towards gauging colony health, the test schedule and time involved in receiving results makes this method ineffective for routine environmental monitoring.

An infection occurring on Day 2 of the quarter would not be found for 15-20 weeks until sentinels were screened and results were returned.

Swab Sampling


Swab sampling, or RODAC plating, involves the manual swabbing of surfaces and plating on growth agar to check for organisms.

Swab sampling can tell you exactly what organism is present through its growth pattern in the agar.

ATP Monitoring


ATP (adenosine triphosphate) is an organic molecule that is used by living cells as their main source of energy and is naturally present in all organic material.

ATP monitors check for ATP from a swab sample that is taken and then inserted into the monitor. If ATP is found, a chemical reaction takes place which emits light and can be measured to produce a numerical value for the ATP present.

ATP Monitoring


ATP monitors pick up live and dead cells, so a “positive” hit on an ATP monitor might not necessarily be detecting an infectious organism but rather a non-viable “dead” organism.

For example, a swab sample taken from a cage w/ bedding would show a positive hit on an ATP monitor even after it went through an autoclave.

Biological Indicators


Biological indicators (BIs) are used to test the efficacy of fumigation methods. They consist of a known level of organisms housed on a carrier material such as paper, plastic, or various metals. BI’s are contained inside a tyvek or glassine pouch which allows the fumigant in but keeps organisms out.

The BIs would be placed around the facility in both open and hard-to-reach areas where the decontamination method is to be tested. Upon completion of the cleaning, BIs are placed in growth media tubes to test for microbial growth.

Biological Indicators - cont


The BIs would be placed around the facility in both open and hard-to-reach areas where the decontamination method is to be tested. Upon completion, BIs are placed in growth media tubes to test for microbial growth.

Some growth media offer color change indication of growth.

On the right, purple is positive for growth and orange is the starting / negative coloration.



To ensure that the decontamination was successful, BIs should be placed in hard-to-reach areas.



To ensure that the decontamination-HEPA Housing-Supply Air Plenum-Return Air Plenum-Small / Large Cage-Cage Water Bottles-Animal Feed Water Tubing



To ensure that the decontamination was successful, BIs should be placed in hard-to-reach areas.

Conclusion


There are many reasons why facility decontamination should take place, both preventatively and in response to a contamination.

It is extremely important to test the effectiveness of your decontamination method to ensure that it is capable of eliminating pathogens and contaminants everywhere, including the hard-to-reach places.

Thank you

Questions?

Kevin Lorcheim Engineer ClorDiSys Solutions, Inc - …labsg.org/lorcheim.pdf · Revision Date: June...

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