Respirator Selection Criteria

The Respirator Selection Guide includes a list of chemicals for which respirators can be recommended. This information can be used to supplement general industrial hygiene knowledge. Once workplace contaminants and their concentrations have been identified, this guide can be used to help select an appropriate respirator for
700 chemicals with Threshold Limit Values (TLVs®) or other recommended exposure limits. Because actual conditions vary from work sites, this information is intended only as a guide. Selection of the most appropriate respirator depends on the situation and should be made only by a person familiar with the working conditions and with the benefits and limitations of respiratory protection products. If you have questions related to proper selection and use of respirators, or use of this guide, please contact our customer care team.

Respirator Fit

The OSHA Respiratory Protection stranded (29CFR 1910.134) requires fit testing for all tight-fitting respirators. Whether you select a filtering facepice (disposable) respirator or a reusable respirator, the wearer must obtain a satisfactory fit as indicated by a qualitative or quantitative fit test. Worker comfort should also be considered. Removal of the respirator, even for short periods of time, dramatically reduces the protection afforded by the respirator.

Assigned Protection Factors (APF)

The respirator selected must have an assigned protection factor (APF) adequate for the particular workplace exposure. Divide the air contaminant concentration by the occupational exposure limit (OEL) to obtain a hazard ratio. Then select a respirator with an assigned protection factor greater than or equal to that hazard ratio.

Hazard Ratio = Airborne Contaminant Concentration/OEL

Assigned protection factors* per OSHA 29 CFR 1910.134 are as follows:

Air Purifying Respirators
• Half facepiece (filtering facepiece disposable and reusable)……….10
• Full facepiece……….50
Powered Air Purifying Respirators
• Loose-fitting facepiece……….25
• Half facepiece………..50
• Full facepiece, helmet, or hood……….1000**
Supplied Air Respirators (airline)
• Continuous Flow
–Loose-fitting facepiece……….25
–Half facepiece……….50
–Full facepiece, helmet, or hood……….1000**
• Pressure demand with full facepiece……….1000

Self-Contained Breathing Apparatus (SCBA)

Pressure demand airline with escape SCBA……….10,000 unknown and IDLH atmospheres
Pressure demand SCBA……….10,000 unknown and IDLH atmospheres

Effects From Skin or Eye Contact

If a chemical can be absorbed through the skin, skin protection may be required in addition to respiratory protection. Eye protection may also be necessary if not provided by the respirator. Failure to provide adequate skin or eye protection can invalidate established exposure limits and make respirator use ineffective for protection against certain workplace contaminants.

Human Factors

Consider the entire package of safety equipment required for the job. The respirator selected must be compatible with hard hats, goggles, glasses, welding hoods, faceshields, etc. In addition, the worker must be able to communicate and perform required job duties without removing the respirator. If strenuous work is to be performed, or if the respirator is to be worn for an extended period of time, it may be desirable to select a lightweight respirator with low breathing resistance. If a respirator does not have good worker acceptance and does not stay on the worker’s face, it will not provide the protection needed.

Location Of Hazardous Area

When specifying supplied air respirators, consider the distance the worker must travel to get to an uncontaminated work area, as well as obstacles or equipment present in the area. If ladders or scaffolds must be climbed, a supplied air respirator or a combination air purifying/supplied air respirator may not be appropriate.

Respirator Characteristics,Capabilities, and Limitations

A respirator may not be able to help protect against all of the contaminants
present in a particular work environment. Specific limitations are stated on the approval labels and are included with User Instructions. These must be carefully reviewed for each respirator before use. General precautionary information is
given below. Refer to respirator packaging or User Instructions for specific information.

General Use Instructions

• Failure to follow all instructions and limitations on the use of these respirators and/or failure to wear them during all times of exposure can reduce respirator effectiveness and may result in sickness or death.
• Many of the contaminants that can be dangerous to a person’s health include the ones that are so small they cannot be seen or smelled at dangerous levels.
• Before use of any respirator, the wearer must first be trained by the employer in proper respirator use in accordance with applicable safety and health standards.
• The OSHA Respiratory Protection Standard [29 CFR 1910.134(f)(1)] requires that the wearer of any tight-fitting respirator be fit tested.
• Leave the contaminated area immediately if dizziness or other distress occurs, if the respirator becomes damaged or breathing becomes difficult, if contaminants can be
smelled or tasted, or if irritation occurs.

General Use Limitations

• These respirators do not supply oxygen.
• Do not use when concentrations of contaminants are immediately dangerous to life or health, when concentrations are unknown, or in atmospheres containing less than 19.5% oxygen.
• Do not abuse or misuse any respirator.
• Do not use tight-fitting respirators or loose-fitting facepieces with beards or other facial hair or conditions that prevent direct contact between the face and the edge of the respirator.
• Do not use when concentrations exceed maximum use concentrations established by regulatory agencies.

Format Explanation

Chemical Name

Chemical names listed in this guide are generally those used in the Threshold
Limit Values and Biological Exposure Indices for 2017 published by the
American Conference of Governmental Industrial Hygienists (ACGIH). Pesticides and chemicals without established occupational exposure limits are not included. Call Our Technical Service for assistance in selecting respirators for these chemicals.

CAS #

Chemical abstract service registry numbers were established by the American Chemical Society to harmonize chemical identification regardless of the synonym used or differences in spelling.

Synonyms

Several common synonyms are listed in this column.

IDLH Level

This is the concentration considered Immediately Dangerous to Life or Health (IDLH), as published by the National Institute for Occupational Safety and Health (NIOSH) (DHHS [NIOSH] Publication No. 90-117). It specifically 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.The reasons NIOSH established an IDLH at a particular level for a specific chemical are described in Documentation for
Immediately Dangerous to Life or Health Concentrations (IDLHs), NTIS Publication No. PB-94-195047, May 1994. The 1994 IDLH values established by NIOSH used interim criteria, and OSHA stated in a May 21, 1996 memorandum that OSHA will use the older IDLH values while NIOSH conducts further study regarding the 1994
values. The 1990 IDLH values are used in this guide since OSHA uses these values
for enforcement. For those substances with no IDLH listed, the manufacturer or supplier may have additional chemical information. The Chemical Referral Center operated by the Chemical Manufacturers Asso ciation can assist in providing telephone numbers for obtaining information from manufacturers. The lower explosive level (LEL) has been listed when an IDLH value was not located. The concentration that would result in an oxygen deficient atmosphere should also be considered to be IDLH.

OEL

• The occupational exposure limits listed are 2017 ACGIH Threshold Limit Values (TLVs), unless otherwise stated. From ACGIH®, 2017 TLVs® and BEIs® Book. Copyright 2017. Reprinted with permission. The concentrations are expressed in ppm — parts per million (parts of contaminant per million parts of air) — unless specifically stated as mg/m3 (milligrams of contaminant per cubic meter of air) or some other unit.
• The OSHA Permissible Exposure Limit (PEL) is listed when it is more stringent than the current TLV.
• The 2010 Workplace Environmental Exposure Levels (WEEL) from the American Industrial Hygiene Association is listed when it is the most stringent value or there is no TLV or PEL.
• Time Weighted Average (TWA) exposure limits are for a normal eight (8) hour workday and a forty (40) hour work-week.
• Short-Term Exposure Limit (STEL) is a 15-minute time weighted average exposure which should not be exceeded at any time during a workday.
• Ceiling (C) exposure limits refer to concentrations that should not be exceeded during any part of the working exposure.
• Exposure limits for particulates are as total dust unless otherwise noted (e.g., inhalable fraction, respirable fraction, respirable fibers, etc.)
• Skin notations indicate the substance can be absorbed through the skin. In these cases, appropriate measures must be taken to prevent skin and eye contact to avoid invalidating the OEL.
• For a more detailed explanation of TLVs and their proper application, refer to the TLV booklet available for a nominal fee from ACGIH, 1330 Kemper Meadow
Drive, Cincinnati, OH 45240 www.acgih.org.

Odor Threshold

Odor thresholds have been removed from this version of the guide. While contaminant odor or irritation may serve as a secondary indicator of when to change cartridges, it cannot be used as the primary indicator for when to change. For more information on odor thresholds, please see relevant publications such as “Odor Thresholds for Chemicals with Established Health Standards, Second Edition. AIHA (2013).”

Respirator Type

This column lists the suggested type of particulate, gas/vapor or supplied air respirator. The abbreviations used are explained at the end of this document. All of these respirators have not been specifically tested against each compound listed. A review of chemical and physical properties of the materials, as well as adsorption or filtration characteristics of the respirators, forms the basis for the recommendations.
The recommendations are for single substances. When two or more substances are present, a combination respirator may be appropriate. For example, with a spray paint that contains organic solvents and titanium dioxide, a respirator consisting of an organic vapor cartridge and a particle filter may be appropriate. In cases where an air purifying respirator is not available for all of the substances of concern in a mixture, a supplied air respirator may be required. In some cases, the respirator is
preceded by an “(F)” designation. These contaminants have been identified as
potential eye irritants. Full facepieces, hoods, helmets or loose fitting facepieces, or half facepieces withappropriate eye protection should be considered. Do not exceed maximum use concentrations established by regulatory agencies. Follow the protection factor guidelines in specific OSHA standards, and refer to the instructions in the Respirator Selection Criteria and How To Use This Guide sections of this guide. When a chemical cartridge respirator is recommended, it can only be used if a cartridge change schedule is established as described in 29 CFR 1910.134 (d)(3)(iii) (B) (2). If a change schedule is not established, a supplied air respirator must be used instead.

Comments

Other information may be listed in this column:

A. Short service life means predicted cartridge life of less than 30 minutes at
concentrations of ten times (10X) the OEL, or the contaminant’s boiling point is less
than 65C. Actual service life will vary considerably depending on concentration
levels, temperature, humidity, work rate, etc. See the following literature references
for specific details on the conditions and limitations of these estimates:

1. 3M Company.
3M Service Life Software.
3M.com/sls

2. Nelson, G.O. and C.A. Harder.
Respirator Cartridge Efficiency
Studies: V. Effect of Solvent Vapor.
Am. Ind. Hyg. Assoc. J. 35(7):
391-410 (1974).

Sometimes, a supplied air respirator is recommended because the service life may be so short that the frequency required for changing the cartridges may not be practical. References to Ineffective sorbents or Unknown sorbent effectiveness indicate 3M does not make chemical cartridge respirators appropriate for these substances at this time or it is not known how effective the sorbents would be for these materials.

B. References to a respirator not being specifically approved refer to approvals for that particular substance only. All respirators listed in this guide are NIOSH approved for specific substances and/or conditions.

C. {Comments regarding warning properties have been removed as OSHA allows air purifying respirators to be used against gases and vapors with poor or unknown warning properties. Instead cartridge change schedules based on objective information and data must be established.}

D. These compounds have been identified as possibly existing in both particulate and vapor phase in the workplace. For these compounds, 3M recommends that a gas/vapor cartridge be used in addition to the traditionally accepted particulate
filter. It is the user’s responsibility to determine whether both forms coexist. Both chemical properties and use conditions/processes can affect the physical form in the
workplace. Users should consider Format Explanation specific exposure data and workplace conditions before making their final selection.* If a chemical cartridge is used, a change schedule must be established to replace the cartridges before the end of their service life.

E. These compounds have been identified as possibly existing in both vapor and particulate phase in the workplace. Even though these chemicals would be expected to be in the vapor phase, when other aerosols are present or there is high humidity, it is possible that the vapor may be adsorbed onto these coexisting particles or dissolved in available water droplets; therefore, 3M recommends a filter for the
particulate phase be used in addition to the traditionally accepted chemical cartridge. It is the user’s responsibility to determine whether both forms coexist. Both chemical properties and use conditions/processes can affect the physical form in the workplace. Users should consider specific exposure data and workplace conditions before making their final selection.*

F. It is believed that an N-series filter is sufficient since these materials will not coat the filter fibers, but since this material may contain oil aerosols, an R- or P-series filter is recommended until further research or a regulatory agency takes a specific position.

G. R- or P-series filters have been recommended pending more research as to how these materials affect the filter fibers.

H. Listing of 3M 3510, 3530, 3550, or 3720 refers to a 3M™ Personal Air Monitor with Pre-Paid Analysis. Monitors may be used to measure the amount of specific contaminants in the air. 3M™ Monitors without pre-paid analysis may be used with analysis performed by a private laboratory. You should check with the laboratory to
determine what other chemicals can be measured with the monitors. An estimate of the airborne concentration is needed for making appropriate respirator selection and establishing a cartridge change schedule.

Particulate Filter Definitions

N-Series Filters: These filters are restricted to use in atmospheres free of oil aero sols. They may be used for any solid or liquid airborne particulate hazard that does not contain oil. Generally these filters should be used and reused subject only to con sid erations of hygiene, damage, and increased breathing resistance.

R-Series Filters: A filter intended for removal of any particle including oil-based liquid aerosol. They may be used for any solid or liquid airborne particulate hazard. If the atmosphere contains oil, the R-series filter should be used only for a single shift (or for 8 hours of continuous or intermittent use).

P-Series Filters: A filter intended for removal of any particle including oil-based liquid aerosols. They may be used for any solid or liquid particulate airborne hazard. NIOSH requires that respirator manufacturers establish time-use limitations for all P-series filters. 3M recommends that in atmospheres containing oil aerosols, P-series filters should be used and reused for no more than 40 hours of use or 30 days, whichever occurs first, unless the filter needs to be changed for hygiene reasons, is damaged, or becomes difficult to breathe through before the time limit is reached. When used in atmospheres containing non-oil aerosol, 3M P-series filters should be used and reused subject to conditions of hygiene, damage and increased breathing
resistance.

Oil: Any of numerous mineral, vegetable and synthetic substances and animal and vegetable fats that are generally slippery, com busti ble, viscous, liquid or liquefiable at room temperatures soluble in various organic solvents such as ether but not in water.

95 Level Filter
At least 95% filtration efficiency per the NIOSH 42 CFR 84 test method.

100 Level Filter
At least 99.97% filtration efficiency per the NIOSH 42 CFR 84 test method.

HEPA Filter
At least 99.97% filtration efficiency per the NIOSH 42 CFR 84 test method. Filter class for powered air purifying respirators (PAPRs) only. Use instead of N, R, P type filters.

How to Use this Guide

If a respirator is being selected for a single compound listed in this guide with an air
concentration not exceeding either the respirator APF times the OEL, or the IDLH, then the respirator identified in the Respirator column may be selected. Descriptions of the respirator codes may be found at the end of this guide. If a particulate filter respirator is recommended (any respirator code with N95, N100, R95, P95 or P100 in it) and a mineral, vegetable or synthetic oil or other oily material is also present in the air, you must select a respirator that provides the same efficiency but is acceptable for oil aerosols (see Oil definition given previously). For example, if a respirator is being selected for beryllium dust at a concentration 2 times the exposure limit, the guide lists N95. If an oil mist is present (air concentration greater than 0.1 mg/m3, but less than the occupational exposure limit) either an Ror P-series filter must be selected, even though respiratory protection is not needed for the oil mist.

For PAPRs, use a HEPA filter instead of the N, R or P type particle filters listed in the guide. If respiratory protection is required for an atmosphere with more than one chemical, you must follow the directions below for proper respirator selection. 

1. Identify the air contaminants present in the workplace. Include chemical name and form. Classify particulate contaminants as oil or non-oil material. If the chemical is listed in this guide, it is classified. For help, see definition of oil. The material safety data sheet (MSDS) can be helpful with this step. Consider particulate contaminants as oil if unknown or not sure. List the contaminants on the form contained in this guide or on your own form. Go to Step 2.

2. Determine the air concentration of the contaminant. Air sampling is highly recommended. Consideration should be given to TWA, short term and peak (ceiling) exposures, while keeping in mind seasonal and worker variability and the specific process being used. If air sampling data are not available and sampling is not practical, historical information from similar processes or analogous operations may be helpful for calculating maximum exposures and evaluating potential health effects. Record the airborne concentration(s) on the form provided or your own form. Go to Step 3.

3. Is the airborne concentration unknown?
a) If yes, go to Step 16.
b) If no, go to Step 4.

4. Is the oxygen concentration less than
19.5% or does the potential exist for the oxygen concentration to fall below 19.5%?
a) If yes, go to Step 16.
b) If no, go to Step 5.

5. Is the chemical listed in the guide?
a) If yes, go to Step 6.
b) If no, go to Step 15.

6. Record the IDLH value and the value from the OEL column on the form provided or on one you created. Determine the hazard ratio (see page 1) and record. Using this
information, determine which condition describes your situation:
a) Does the airborne concentration exceed the IDLH value? If yes, go to Step 16.
b) Does the hazard ratio exceed (>) 1000? If yes, go to Step 16.
c) Does the hazard ratio exceed (>) 50?If yes, go to Step 7.
d) Does the hazard ratio exceed (>) 10? If yes, go to Step 8.
e) Is the hazard ratio less than or equal to (≤) 10? If yes, go to Step 9.

7. If the hazard ratio exceeds 50, but is less than 1000: Select one of the following
respirators:

(1) a full facepiece, helmet or hood supplied air respirator or

(2) a full facepiece, helmet or hood powered air purifying respirator (PAPR) with the same cartridge type as listed in the guide under the Respirator column. If a PAPR is selected, use a HEP A filter if an N, R, or P-series filter is listed. If the guide lists SA or SA(F), a PAPR cannot be used. If a gas or vapor respirator is selected, cartridge change schedules based on objective data must be established. Otherwise supplied air respirators must be used. The service life of gas or vapor cartridges should be considered to determine if supplied air respirators are a better selection given the high exposure concentrations. Record the respirator you selected in the last column of the form for that chemical. Go to Step 10.

8. If the hazard ratio exceeds 10 but is less than 50, select one of the following respirators:

(1) If the guide lists SA or SA(F), a supplied air respirator must be used. Loose fitting facepieces may only be used if the hazard ratio is less than 25.

(2) A powered air purifying respirator (PAPR) may be used with the cartridge and/or filter type listed under the Respirator column. Use a HEPA filter if an N, R, P-series filter is listed. Loose fitting facepiece may only be used if the hazard ratio is less than 25.

(3) A full facepiece respirator that has been quantitatively fit tested may be used with cartridges and/or filters listed under the Respirator column. If a gas or vapor respirator is selected, cartridge change schedules based on objective data must be established. Otherwise supplied air respirators must be used. Record the respirator you selected in the last column of the form for that chemical. Go to Step 10.

9. If the hazard ratio is less than or equal to 10: Select the respirator type listed in the respirator column. If a gas or vapor respirator is selected, cartridge change schedules based on objective data must be established. Otherwise supplied air respirators must be used. Record the respirator you selected in the last column of the form for that chemical. Go to Step 10.

10. Are any other air contaminants present at the same time?

a) If yes, go to Step 2 and repeat the procedure, recording the appropriate information for the next chemical. When two or more contaminants that act upon the same organ system are present, consideration should be given to the combined effect rather than individual effects. Consult the current TLVs® and documentation published by the American Conference of Governmental Industrial Hygienists for more information and the appropriate formula. If combined effects are considered, calculate the hazard ratio for the mixture.

b) If no, go to Step 11.

11. Are any of the respirators listed in the last column a particulate filter respirator (i.e., does it have an N, R or P filter?)?

a) If yes, go to Step 12.
b) If no, go to Step 14.

12. Are only N-series particulate filter respirator(s) listed?

a) If yes, go to Step 13.
b) If no, go to Step 14.

13. Is airborne oil mist present at a concentration greater than 0.1 mg/m³ but less than the value in the OEL column of the guide? (If a respirator is not being selected for oil, the presence of the oil must still be considered when choosing the appropriate filter.)

a) If yes, a respirator with either an R- or P-series or HEPA filter must be selected. R-series filters must be changed after 8 hours use or after the respirator is loaded with or exposed to 200 mg of aerosol. The manufacturer’s service time recommendation must be followed for P-series filters. Record the respirator with the R- or P-series filter that is being selected. Go to Step 14.

b) If no, go to Step 14.

14. Was more than one respirator type required for the specific exposure situation (i.e., is there more than one respirator code included in the list made in the last column of the form?)?

a) If yes, note all respirators recommended. If your list contains more than one respirator and all are air purifying respirators, select the one with the highest assigned protection factor (see page 2) and one that removes all of the contaminants, if available. If SA or SA(F) is one of the respirators listed, this respirator must be selected over all others. If any of the respirator codes contain the (F) designation, respirators with half facepieces cannot be used unless appropriate eye protection is also worn. If no air-purifying respirator will provide the protection required, select SA or SA(F). Go to Step 17.

b) If no, record the respirator listed as the final respirator selected (bottom line). Go to Step 17.

15. If the chemical is not listed in the guide, either it is a pesticide or an occupational
exposure limit was not located. If an acceptable exposure level is not known, a respirator cannot be recommended. If you have an exposure level for the material and would like help, go to Step 17. If no exposure limit is known, go to Step 16.

16. These conditions (unknown, <19.5% oxygen, airborne concentration >IDLH) are generally considered as IDLH or the hazard ratio exceeds 1000. Select either a positive pressure self-contained breathing apparatus (SCBA) or combination respirator consisting of a positive pressure supplied air respirator with an auxiliary
SCBA. The rated duration of the auxiliary
SCBA should be sufficient to allow adequate time for escape. Record the respirator selected in the final row of the form. This is the minimum acceptable level of respiratory protection; the selection process is finished. 

17. Do you need help?
a) If yes, contact Us for assistance

b) If no, order the selected respirator(s) from your local safety equipment distributor.