Personal Protective Equipment And Clothing - NCBI Bookshelf - NCBI

Personal protective equipment and clothing may act as barriers to minimize the risk of exposure to aerosols, splashes and accidental inoculation. The choice of clothing and equipment depends on the nature of the work. Protective clothing should be worn whenever staff work in the laboratory (see Box 6). Before leaving the laboratory, staff should remove their protective clothing, and wash their hands. Table 5 summarizes the types of personal protective equipment used in laboratories and the protection each type offers.

Box 6

Guidelines for the use of gloves and respirators according to the risk level of the tuberculosis (TB) laboratory. This guidance summarizes the minimum requirements for the use of this equipment at the different biosafety levels in TB laboratories. Respirators (more...)

Table 5

Personal protective clothing and equipment that may be used in by staff in tuberculosis (TB) laboratories.

7.1. Laboratory gowns

Laboratory gowns should have long sleeves and open in the back. When the laboratory technician is standing, the gown must extend below the height of the workbench; the gown should fully cover the technician's lap when he or she is sitting. Reusable gowns should be autoclaved before being washed. Gowns must not be taken home for washing; laundering services should be provided at or near the facility. Laboratory gowns should be changed at least once a week and immediately after being overtly contaminated.

Laboratory gowns should not be worn outside the laboratory. A changing area should be available where gowns can be stored. All laboratory staff, as well as all others entering the laboratory, must wear a gown. Protective laboratory clothing should not be stored in the same lockers or cupboards as street clothing. Extra gowns should be available in case of contamination.

7.2. Respirators

Respirators are not normally required for work in a TB laboratory. However, they may be recommended after a risk assessment if cultures are being manipulated within a TB-containment laboratory. Even if not worn regularly, respirators must be available in laboratories where culture manipulations are performed in case an accidental biohazard (such as a spill) occurs outside the BSC. Respirators should be included as part of a laboratory's spill clean-up kit.

Respirators should never be used as a substitute for a properly maintained and functioning BSC.

N95 (United States Standard NIOSH N95) or FFP2 (European Standard EN149:2001) respirators should be worn if indicated by a risk assessment. Such respirators are lightweight, disposable devices that cover the nose and mouth and filter 94–95% of particles that are ≥0.3–0.4 μm.

If respirators are used in a laboratory, all staff should be instructed and trained in their proper use and fitting, and in their limitations. Ideally, staff should undergo a fit test to ensure leakage does not occur. Respirators should not be used by people with facial hair. Respirators must be stored in a convenient, clean, dry and sanitary location, and must not be worn outside of the laboratory. Once a respirator has been put on, under no circumstances should the wearer touch the front of it. Staff should not place the respirator under their chin or on their head when answering the phone or talking.

Respirators must be inspected before every use to ensure that there are no holes other than the punctures around the staples, and to ensure that no damage has occurred. (Enlarged holes resulting from ripped or torn filter material around staple punctures are considered to be damage.) Straps and valves must also be checked. A damaged respirator must be discarded and replaced immediately.

Surgical masks are not respirators, are not certified as such and do not offer significant protection to personnel performing aerosol-producing diagnostic tests for TB. They are not designed to protect the wearer from inhaling small infectious aerosols and therefore should not be used.

7.2.1. Fitting a respirator

Staff who use respirators must be trained. They should be taught to:

• cup the respirator in one hand, with the nosepiece at the fingertips; they should allow the headbands to hang freely;
• position the respirator under the chin with the nosepiece upwards; pull the top strap over their head and place it high at the back of the head; pull the bottom strap over the head and position it around the neck below the ears;
• place the fingertips of both hands at the top of the metal nosepiece; using two hands, mould the nose area to the shape of their nose by pushing inward while moving their fingertips down both sides of the nosepiece; pinching the nosepiece with only one hand may result in an improper fit and less effective respirator performance; they should always use two hands.

7.2.2. Removing a respirator

• Staff should remove their gloves and thoroughly wash their hands before removing respirators. Only the straps should be handled; staff should avoid touching the front of the respirator.

7.3. Gloves

Gloves must be worn for all procedures that involve direct contact, or may involve accidental contact, with sputum, blood, body fluids and other potentially infectious materials. After use, gloves should be removed aseptically and hands washed.

Contaminated gloves (and unwashed hands) may be a source of infection for other staff members if they are used to handle or operate equipment in the laboratory (such as a centrifuge or telephone).

Regular hand washing is essential to prevent many types of laboratory-acquired infections, including those caused by bloodborne pathogens.

Disposable latex, latex-free vinyl (clear) or nitrile gloves can be used, and the correct size (small, medium or large) should be available for all individuals. Gloves should fit as comfortably as possible and should cover the wrists.

Disposable gloves must never be reused, and once they have been used they should be discarded with infectious laboratory waste. There must be a reliable supply of gloves. Gloves should not be worn outside the laboratory.

Staff should remove gloves and wash their hands thoroughly with water and soap after handling infectious materials, working in a BSC, and before leaving the laboratory.

7.3.1. Removing gloves

Laboratory staff should be trained to remove their gloves by following these steps:

1. peel one glove off by grasping it under the cuff and rolling the glove off the hand so that it comes off inside out. This keeps most of the contamination inside;
2. hold the used glove in the opposite still-gloved hand. Carefully slip exposed fingers under the cuff of the gloved hand, being careful not to touch the surface of the contaminated glove. Peel the glove off, inside out, rolling it over the other used glove to form a bag of used gloves with contamination inside.
3. Dispose of the gloves properly and safely.