Respiratory Protection

AIHA Publishes Body of Knowledge on IAQ, Respiratory Protection, and Direct Read Instruments


AIHA has begun publishing technical documents that represent the “body of knowledge” that a competent and skillful practitioner should possess.  The documents are available for free on AIHA’s website and currently consists of the following:

More BoK documents are in development.

Source: AIHA BoK

Odor Thresholds, TLVs, OELs, IDLHs, and Respirator Selection Guide for Chemicals

3M Corporation put together a respiratory protection guide (download link at end of this article) that contains a wealth of information for OH&S professionals including:

  • Immediately Dangerous to Life or Health (IDLH) levels
  • Odor Thresholds
  • Occupational Exposure Levels (OELs)
  • Respiratory Protection Selection Guide

IDLH’s are published by NIOSH and “refers to the acute respiratory exposure that poses an immediate threat of loss of life, immediate or delayed irreversible adverse effects on health, or acute eye exposure that would prevent escape from a hazardous atmosphere.”

With reference to odor thresholds it should be noted:

The method of defining and determining odor thresholds varies widely, thereby giving rise to a significant range of reported odor thresholds for many substances. Individuals may also respond differently to the same odor. At a given concentration, one person may smell and recognize the odor, while another person may barely notice it. The odor thresholds reported in the literature are typically determined for a single constituent, with no other chemicals present in the air. The single constituent situation rarely occurs in the workplace. Therefore, caution must be exercised in using these numbers.

Referenced OELs are based upon ACGIH’s TLVs, except where noted in the chart.


Differences Between a Respirator and a Surgical Mask

Want to know what the general differences between a respirator and a surgical mask?  Watch the following video.

In summary,

A respirator:

  • reduces exposure to airborne contaminants
  • specifically fits you
  • must be NIOSH certified, if required by your employer
  • protects against many airborne infectious diseases

A facemask:

  • loose fitting disposable mask
  • help stop large droplets from being spread by the person wearing it
  • help stop particles from reaching the mouth/nose of the person wearing it
  • airborne particles can reach the individual wearing it via gaps
  • FDA approved

Surgical N95 respirators:

  • provide respiratory protection in the healthcare setting
  • should be used in conjunction with other controls (engineering & administrative)

AIHA Releases White Paper on the Need for Respiratory Protection Research

respiratory_protectionThe American Industrial Hygiene Association (AIHA) recently released a white paper on the need for research of respiratory protection to “enhance the safe and effective use of respiratory protection.”

Among the research needs are:

  1. Measurement of respirator performance
  2. Qualitative fit testing for full facepiece respirators
  3. Appropriateness of fit factor safety margin criterion
  4. In-facepiece measurements
  5. Effectiveness of respiratory protection program requirements
  6. Effectiveness of user seal checks
  7. Organic vapor cartridge desorption

A copy of the full white paper can be found HERE:

  PPEPPTGeneralIndustry1.ppt (5.1 MiB, 2,053 hits)

Many current practices in respiratory protection are based on assumptions, past practices or extrapolation from laboratory studies. Few studies have been done to evaluate the efficacy of, or the need for, each of these practices. AIHA believes the results of research on the practical, applied topics presented in this paper may significantly enhance the safe and effective use of respiratory protection.


Approved NIOSH N-95 Respirators

n95_respiratorThe N95 respirator is the most common of the seven types of particulate filtering facepiece respirators. This product filters at least 95% of airborne particles but is not resistant to oil.

View the complete list of approved N-95 respirators HERE

A list all of the seven types of particulate filtering facepiece respirators is shown below:

Class Description
N95 Filters at least 95% of airborne particles. Not resistant to oil.
N99 Filters at least 99% of airborne particles. Not resistant to oil.
N100 Filters at least 99.97% of airborne particles. Not resistant to
R95 Filters at least 95% of airborne particles. Somewhat resistant
to oil.
P95 Filters at least 95% of airborne particles. Strongly resistant
to oil.
P99 Filters at least 99% of airborne particles. Strongly resistant
to oil.
P100 Filters at least 99.97% of airborne particles. Strongly resistant
to oil.

N95 Respirator Training and Fit Testing Verification Card


A copy of the N95 Respirator Training and Fit Testing Verification Card can be download HERE: (

  MachineGuardingPPT.ppt (3.2 MiB, 2,023 hits)


During a recent AOHP/OSHA Alliance conference call that included the National Personal Protective Technology Lab (NNNPTL), a need was identified for healthcare workers to easily recall the type of N95 respirator for which they had been trained and fitted. The Alliance decided to create a generic card to document this important information. Ideas were brainstormed and the N95 Respiratory Training and Fit Testing Verification Card was created. It also includes tips for correctly donning/doffing PPE.

From the Association of Occupational Health Professionals in Healthcare

New Guidance Document – Assigned Protection Factors

apfOSHA has issued a new guidance document for employers who may need to establish and implement a respiratory protection program due to potential exposures to contaminants in workplace air.  The document focusues on the mandatory selection provisions of the assigned protection factors (APFs), maximum use concentrations (MUCs) and the use of the APF Table 1 of 29 CFR 1910.134.  A limited number of copies are available for ordering from:

1. OSHA’s publications page

2. Calling 202-693-1888, or

3. Download HERE