N95 Respirators for TB Lab Personnel

N95 respirators are Personal Protective Equipment (PPE) used as a biosafety measure in clinical and laboratory settings.

N95 Respirators

• N95 filtering facepiece respirators are air-purifying respirators.
• Certified to have a filter efficiency level of 95% or greater against particulate aerosols free of oil and 0.3 microns in size.
• N95 (United States Standard NIOSH N95) or program-specific guidelines should be followed in the selection of these respirators.

Figure: N95 Respirators

Use of N95 Respirators in TB Laboratories

• Not required in low- and moderate-risk TB laboratories but are required in high-risk TB laboratories
• Must be available in laboratories where culture manipulations are performed
• Should be included as part of a laboratory’s spill clean-up kit
• Should never be used as a substitute for a properly maintained and functioning Biosafety Cabinet (BSC) and other PPE

Approval Required for N95 Use

Personnel who are required to wear respirators, shall be approved for N95 use after completing the following:

• Medical Evaluation/ Clearance: To determine if users are physically fit to wear a respirator.
• Training: To ensure users are familiar with N95 respirators, their proper use and protective limitations.
• Fit-testing: To determine which respirator model/ size provides the proper fit for the user. Such a fit-test is required on an annual basis and when a different model is being used or there are changes in facial characteristics.

Limitations of N95 Respirators

• N95 respirators ONLY filter out particulate contaminants. N95 respirators do not protect from chemical vapours/ gases, high-risk exposures such as those created by aerosol-generating procedures (i.e., bronchoscopy, autopsy) and asbestos handling.
• N95 respirators are generally single-use disposable. Considering the funding constraints for TB labs, the availability of N95 can pose a challenge.

Comparison between the Surgical Mask and N95 Respirators

• The purpose of a surgical mask is to protect the environment or the community from the wearer of the mask. It is usually worn by a patient infected with TB or other infectious diseases to protect others.
• Unlike the N-95 respirator, a surgical mask offers less protection to the wearer from aerosolized TB and is unable to form a tight seal; thus aerosols are able to come in through the gaps.

Disposal of N95 Respirators

• TB lab personnel must remove the mask using the appropriate technique (i.e., must not touch the front but remove the lace from behind), only after coming out of the laboratory.
• Staff must clean their hands by using an alcohol-based hand rub or soap and water, after removal or whenever inadvertently touching a used mask.
• N-95 mask must be discarded and collected in separate 'yellow colour-coded plastic bags' (suitable for biomedical waste collection).

Resources

• National Guidelines for Infection Prevention and Control in Healthcare Facilities, 2020. Ministry of Health and Family Welfare, Government of India.
• Importance of a User Seal Check, Manual from 3M Science.
• Frequently Asked Questions about Respiratory Protection by Center for Disease Control and Prevention (CDC).

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