PPE is perhaps the most important aspect of health and safety within the laboratory, whether it is viral research in containment laboratories or dissection in histology departments. Either way, the crucial element of safety is self-protection via Personal Protective Equipment. However, safety does not stop with simple donning of PPE. To prevent cross-contamination, users must follow a strict procedure, in view of protecting the integrity of laboratory procedures.
Containment laboratories are the most important to get right. Aside from masks – usually p3 half face respirators or full-face masks or hoods – there is a full range of PPE which is used in order to fully isolate the body from the environment in which you are working. It is critically important to get the donning and doffing procedure for PPE correct, in order to protect your own health, the integrity of the research, and ultimately protect all people. This applies particularly to viral research where containment relies on the care people in the lab take when donning and doffing to ensure absolute containment – a lot of speculation exists in this regard, relating to a biosafety lab in Wuhan, for one reason or another.
Steps to minimise risk of cross-contamination
1: Gloves
Pre-donning gloves, used usually in sterile environments, must be put on with care so as to ensure contaminants are not spread to the glove fingertips.
This step will ensure that when putting the rest of the PPE on, contaminants are not spread throughout the process, which would make the PPE highly ineffective.
Take the glove by the cuff, taking care to touch the externals as little as possible.
2: Caps/Shoe Coverings/Glasses
Take your bouffant cap and ensure you handle the inside of the cap, stretching to pull over your hair. Make sure hair is all contained and covered by the cap. Likewise, do the same with shoe covers, so that all laces, tassels etc are covered.
When donning glasses, ensure you select the correct ones, then inspect and clean before donning.
3: Mask
Carefully fit your mask – whether N95 or P3 and ensure it is fitted and sealed properly. Bend the nosepiece to ensure the mask is effective. If wearing a full-face mask or a hood, ensure it is sealed properly by inspecting or asking a colleague to inspect all seal points. If this is required, most likely you will be in a separate room designed for safe donning. Ensure the face and neck are both secure and there are no defects with the product.
4: Gowns
Don your coverall or gown using gloves and ensuring no part touches the floor. If using a full coverall or hazmat gown with a hood, tuck the hood inside the shoulder for proper fit.
If required, don your second pair of boot/shoe covers to ensure maximum protection.
5: Gloves
The final step will be to don a clean pair of gloves over the donning pair. Ensure the gloves are again handled by the cuff, and that the glove is pulled over the sleeve cuff of the gown.
You are now ready to enter the laboratory!
Before Donning:
Ensure that, aside from standard PPE, protection is provided by exercising particular care over personal care, cosmetics and clothing. Appropriate protocol must be in exercise and all personnel well versed and trained in standard operating procedures.
- Cosmetics – minimise personal care items such as lotions/gels/make-up/skin care in order to prevent contaminants
- Smoking – particles will be airborne and will spread for a long period after the smoker has stopped. Set minimum timeframes from smoking to entry of the lab. One hour should be benchmark to ensure contaminants are not spread.
- Remove unnecessary items before donning PPE, such as sunglasses, hats, jackets, large jewellery etc. before entering the donning room to minimise risk when donning, and to make the procedure simpler.
- Plan out all processes from entry to exit of the lab and ensure personnel are trained and can execute tasks efficiently and properly. Lay out workflows in advance in the laboratory to minimise the number entries/exits to the laboratory and thus minimise risk of contamination.
Doffing
Taking your PPE is usually executed in the reverse order of which it was put on. However, the exception is with the gloves, which are taken off last. If there is a second pair of gloves worn, these will be taken off first, and the donning gloves taken off last.
When removing reusable items such as hoods, coveralls or glasses, ensure these are placed in the correct procedure, and are disinfected and properly cleaned before placing in storage.
Making sure that procedures for donning and doffing are well documented and rehearsed will make the process efficient and effective.
Ensure ultimate caution is taken when handling PPE, as this will provide increased safety.
These steps can never be taken too seriously, as failure to follow correct protocols, whether in a containment laboratory or in classroom experiments, will expose users to risk. In higher security labs, this could potentially have disastrous effects.
