How to Use This Guide

The Response Respirator Selector presents certain basic information for guidance purposes only. Although more comprehensive than any comparable guide, it is not all inclusive in content or scope. For more complete information on specific respiratory hazards and problems, please refer to the publications listed below and the Occupational Safety and Health Administration (OSHA) or Nuclear Regulatory Commision (NRC) standards listed.

OSHA Standards

Nuclear Regulatory Commission

How to Use This Guide

The Response Respirator Selector is designed to help you in the respirator selection process using a format that is easy to read and understand. A key to this guide is the Hazard Identification section.  Once you have identified the chemical of interest in the Hazard Identification section, move left to right to find a series of Response Codes that identify appropriate respirator types and, if necessary, air-purifying element types.

STEP 1

Determine if the respirator will be used for fire fighting.  If so, select an Air Mask from category E1 or E3.  If the respirator will not be used for fire fighting, proceed to step 2.

STEP 2

Determine if the atmosphere is deficient in oxygen (less than 19.5 percent). If so, select a respirator from categories E1, E2, E3 or E4.  If not deficient in oxygen, proceed to Step 3.

STEP 3

Determine if the atmosphere has the potential to become deficient in oxygen (less than 19.5 percent).  If so, select a respirator as follows, based on the application for which the respirator will be used:

STEP 4

Locate the chemical of interest (listed alphabetically) in the Hazard Identification section of this book.  Each chemical listing includes the following:

Use the respirators recommended only for protection against the specific chemical or its synonyms identified in the Hazardous Identification Section. Use against other contaminants can result in overexposure to that contaminant and cause serious injury or death. If mixtures exist, follow the procedure in step 9.

STEP 5

Compare the chemical concentration at your facility (determined by air sampling) with the chemical's exposure limits.

STEP 6

If the chemical concentration at your facility is less than the lowest exposure limit, no respirator is needed. However, one may be used for nuisance levels.  If the concentration is greater than the lowest exposure limit, use of a respirator is recommended.

STEP 7

To locate the respirator category you need, consult the "Maximum Use Concentration-Routine Use," or the "Maximum Potential Concentration - Escape" columns.  If a respirator is to be used for both routine and escape use, review both columns and select a respirator that provides adequate protection for both situations.  An appropriate respirator is one that has a maximum use concentration or a maximum potential concentration greater than or equal to the chemical concentration at your location.  Read to the right to find the alphanumeric Response Code that is appropriate for that level.

In selecting a respirator, it is important to note that recommendations in the Response guidebook are based on a suitable, minimum level of respiratory protection.  If you desire, a higher level of protection can be used by selecting a respirator with a higher maximum use concentration or, if applicable, a higher filter efficiency.  This, of course, would be advisable if the atmosphere in the work area is prone to changes and the contaminant concentration has the potential to become higher.

STEP 8

If an air-purifying element is required with a particular MSA respirator, the type of protection required is located to the right of the alphanumeric Respirator Code. In the far right column, the primary MSA purifying element is listed. The Purifying Element Charts provide information about capabilities and range of compatible purifying elements for various types of respirators.

STEP 9

When mixtures of contaminants exist, you will need to perform some relatively simple calculations to determine which respirator category is appropriate for your particular mixture.  The mathematical equations below, which are derived from the Threshold Limit Values booklet (published by the ACGIH), will assist you in making this determination.

The second step is to determine the TLV of the mixture or T_Mixture. The TLV of the mixture is determined using the following formula, where T1, T2, T3 ... are the individual contaminant TLVs and C₁, C₂, C₃ ... are the individual contaminant concentrations:

Only use these equations if the contaminants present are actually mixed. Some substances do not mix and may be present separately, for example, in pockets or at different levels. In that case, the lowest TLV of the substances present must be used to determine the appropriate respirator category for protection against all contaminants present.

If the mixture is determined not to be IDLH, then a respirator selection can be made using the following Response guidelines for routine use and/or escape.

*See Response Product MiniGuide and Purifying Element Charts for information on respirators within these RESPONSE codes.

Final Word
As its name implies, the Response Respirator Selector responds to your need to simplify the task of choosing appropriate respiratory protection. It is just one part of MSA's commitment to provide superior customer service.  With MSA, you also have access to the most dedicated and highly trained staff of personal protective equipment experts. We encourage you to use them.