OSHA/NIOSH Interim Guidance (April 2005)
Chemical - Biological - Radiological - Nuclear (CBRN) Personal Protective Equipment Selection Matrix for Emergency Responders
RED ZONE: Areas where significant contamination with chemical, biological, radiological, or nuclear (CBRN) agents has been confirmed or is strongly suspected but area has not been characterized. The Area is presumed to be life threatening from both skin contact and inhalation.
YELLOW ZONE: Areas where contamination with chemical, biological, radiological, or nuclear (CBRN) agents is possible but active release has ended and initial monitoring exists.
GREEN ZONE: Areas where contamination with chemical, biological, radiological, or nuclear (CBRN) agents is unlikely. This zone covers the area beyond the expected significant dispersal range of the initial event and secondary contamination range caused by traffic and emergency responders.
Introduction
Recent terrorist events in the United States underscore the importance of emergency response procedures for dealing with terrorist-related events involving chemical, biological, radiological, or nuclear (CBRN) agents. OSHA and NIOSH continue to work with other Federal response agencies to provide accurate, current information to help prepare these on-scene responders.
Personal Protective Equipment (PPE) for CBRN Response
Emergency response to hazardous substance releases including CBRN are guided under OSHA's Hazardous Waste Operations and Emergency Response (HAZWOPER) Standard (29 CFR 1910.120(q)). Personal protective equipment is selected to meet the requirements of this standard and Subpart I. NIOSH has developed a respiratory protection approval specifically for CBRN exposures and the Department of Homeland Security also adopted guidelines for appropriate PPE. In order to use this guidance effectively, an employer must assess the risk of a hazardous substance release to the emergency responders and base the PPE selection on the level of knowledge relative to that risk. This kind of assessment is a typical safety and health evaluation with the unusual caveats that many of the agents are highly toxic by both skin and inhalation, typical indicators of exposure such as odor, smoke, or fume may not be present, exposure monitoring is difficult for some of the compounds, and there may be a locally limited supply of CBRN-approved respirators for a large response during initial emergency operations. Based on the hazardous substances and conditions known to be present, the Incident Commander in charge of a response shall implement appropriate emergency operations, including selection of appropriate PPE for employees who respond. This includes, at a minimum, PPE meeting the criteria in 29 CFR 1910.156(e) for fire fighting operations beyond the incipient stage, 29 CFR 1910.120(q)(3)(iii).
Site Control
Site control is an important part of managing any emergency response operation. Some guidance for zoning exists in 29 CFR 1910.120 Appendix C and in the NFPA 471 Standard (2002) (Hot, Warm, Cold) with hot denoting a contaminated area where adverse effects might be seen, warm being an initially clean area for close support and decon, and cold representing an area with no potential exposure. Other guidance from the DOT Emergency Response Guidebook provides for an "Initial Isolation Zone" where dangerous or life threatening concentrations of a substance may exist or a "Protective Action Zone" where serious or irreversible health effects may be seen. The OSHA zones of Red, Yellow, and Green described below are available to be used by incident commanders as complimentary guidance for personal protective equipment selection based on the level of knowledge about the WMD events. The use of the Red, Yellow, and Green zones is not mandatory nor exclusionary of other site control concepts. It is intended to offer flexibility to an incident commander managing a large WMD event within the limitations of current first responder monitoring capabilities.
RED ZONE
Areas where significant contamination with chemical, biological, radiological, or nuclear (CBRN) agents has been confirmed or is strongly suspected but area has not been characterized. The Area is presumed to be life threatening from both skin contact and inhalation.
Level A protection is generally needed when the active release is still occurring, or the release has stopped but there is no information about the duration of the release or the airborne concentrations of CBRN agents. Respirators chosen initially for responders going into a known release area where CBRN are suspected should be a positive pressure self contained breathing apparatus (SCBA) with a fully encapsulating protective suit until monitoring results allow for other decisions. Level A protection should be consistent with the description in HAZWOPER Appendix B and suits should be appropriate for CBRN agents. e.g. meets the requirements of NFPA 1994-2001, has been tested by a third party such as the U.S. Army and Soldier and Biological Chemical Command (SBCCOM), or has undergone other manufacturer testing. A NIOSH-certified CBRN SCBA respirator should be used, if available.
Other prudent work practices should include minimizing exposure time to that essential for lifesaving or initial monitoring, avoiding any unnecessary contact with surfaces or potentially contaminated material, use of natural ventilation flows to reduce exposure, mandatory decontamination and post exit evaluation for signs and symptoms of exposure.
YELLOW ZONE
Areas where contamination with chemical, biological, radiological, or nuclear (CBRN) agents is possible but active release has ended and initial monitoring exists.
Areas in close proximity to the release area or that are known to be contaminated and certain job activities on the periphery of the event area should be considered for this zone. Risk factors that should be considered include determining the relative risk for job activities from inhalation based on available air monitoring results, skin contact and absorption potential, proximity to the event, and wind directions. Refer to the specific hazard information pages below to select personal protective equipment and limited work durations to reduce exposure to safe levels. Use the other prudent work practices listed above for red zone exposures.
GREEN ZONE
Areas where contamination with chemical, biological, radiological, or nuclear (CBRN) agents is unlikely. This zone covers the area beyond the expected significant dispersal range of the initial event and secondary contamination range caused by traffic and emergency responders.
Even in areas which are not thought to pose a hazard, there may be a concern or potential for a minimal level of transient or unknown exposures in the aftermath of an event. The following suggestions for prudent work practices may reduce the amount of concern regarding this potential:
- Inform people of location of event and control zones.
- Provide information regarding signs and symptoms of exposure.
- Suggest a means for reporting suspected exposures.
- Suggest attention to general hygiene practices.
- Provide information on voluntary use of personal protective equipment.
Specific Hazard Information
Related Online Resources
NOTICE
This product is not a standard or regulation, and it has no effect on employers' legal obligations. The guidance is advisory in nature, informational in content, and is intended only as technical assistance to employers in providing a safe and healthful workplace during emergency response operations. This document does not enhance or diminish any existing obligations under the OSH Act. The information in this document is interim guidance only. It is anticipated that NIOSH CBRN approval for all classes of respirators will be available in the near future. This guidance will change at the time NIOSH CBRN certification standards are available for all respirator classes. OSHA also may update this guidance as additional information becomes available in the future.
Nerve Agents
Introduction
Nerve agents consist of a group of very toxic organophosphate chemicals specifically designed for military warfare. These include the agents code-named GA (Tabun), GB (Sarin), GD (Soman), Cyclohexyl Sarin (GF), and VX.Other organophosphate chemicals include commercial insecticides such as Malathion®. These chemicals all cause similar effects on the human body by disrupting how nerves communicate and control muscles, glands, and organs. Though they cause similar effects, nerve agents are more toxic than commercial insecticides -- so smaller amounts can cause effects of concern. Most of the nerve agents exist as liquids but some (such as GB) volatilize into the air on their own. VX is the least likely to become airborne, but in conditions involving explosions, it could vaporize and spread in the air.
Personal Protective Equipment
The recommendations for personal protective equipment (PPE) should be based on a site-based job hazard analysis of possible hazards including skin contact, air concentrations, heat stress, etc. All PPE should be used with appropriate additional administrative controls including medical surveillance, employee training, respirator fit-testing, and decontamination procedures to limit the potential for unforeseen adverse effects.
There are no current OSHA Permissible Exposure Limits (PELs) for exposure to nerve agents. The National Research Council and EPA have published airborne limits to various agents called Acute Exposure Guideline Levels (AEGLs) to characterize the risk to the general population during a one-time accident and emergency scenario with time limits not to exceed 8 hours of exposure. For emergency responders and support personnel to a nerve agent event, it seems appropriate to establish a target exposure limit at time weighted averages less than the lowest recommended AEGL-1 level for a given exposure duration. The AEGL-1 tier is the mildest effect category above which the general population, including susceptible individuals, could experience noticeable eye discomfort, irritation, or non-sensory effects. However, the effects are not disabling and are reversible upon cessation of exposure. The AEGL-1 and AEGL-2 values are based upon direct vapor exposure to the human eye and tissues surround the eye (conjunctiva), which are considered the most sensitive organ/tissue for blister agent vapor exposure effects by the National Research Council and the National Academy of Sciences. The CDC has made recommendations for worker exposure limits dealing with routine work processes such as demilitarization and transportation. Note: The CDC/NCEH worker exposure limits do not specifically include storage. These exposure standards may be substituted for work extending beyond the 8-hour AEGL limit if deemed appropriate after an incident.
The PPE ensemble selected depends on the level of knowledge available regarding the chemical agent. Respirators chosen initially for responders into a known release area should be a positive pressure self-contained breathing apparatus (SCBA) with a Level A protective suit until monitoring results allow for other decisions. OSHA would generally require these respirators to be NIOSH-certified CBRN SCBA respirators for use by employees. Some chemical warfare agents have been shown to seriously degrade and damage some respirators. Respiratory protection specifically approved by NIOSH for CBRN exposures is highly desirable but where not available, the incident commander may allow alternative suitable respirators during emergency operations. These are, depending on exposure levels, other NIOSH approved SCBAs or full-face air purifying respirators, which have been specifically tested by the manufacturer as effective against chemical warfare agents. Respirators other than SCBAs may be selected based upon accurate monitoring results with appropriate limits of detection for the subject agent. When conditions have been determined to be appropriate for the use of air purifying respirators, a NIOSH-approved CBRN APR Full Facepiece Air Purifying Respirator (APR) with a CBRN Canister, or a Chemical Warfare Agents (CWA) tested full facepiece APR with a combination organic vapor/acid gas/particulate canister may be used. A list of CBRN approved SCBA and APR may be obtained from the NIOSH website - APR or SCBA.
The tables below consolidate some information provided by other agencies relating to toxicity, exposure, and the relative protection provided by certain types of respirators and clothing. These limits are for planning purposes and are not recommendations for particular work schedules. Any work schedules should be reviewed by a competent occupational health professional skilled in use of exposure limits and PPE. Respiratory protection and other PPE recommendations are presented in the table below as time-dependent exposure limits by multiplying the NIOSH current assigned protection factor (APF) of the type of respirator and the AEGL-1 target level. Exposures above the limit require a more protective respirator. It should be noted that OSHA's proposed rule on APFs indicate that some hooded or helmeted powered air-purifying respirators have much higher protection factors than the current APF of 25. However, this rulemaking is pending and subject to change. The US Army's Immediately Dangerous to Life or Health (IDLH) level is set as the ceiling limit for respirators other than SCBAs. Any exposures approaching the IDLH level should be regarded with extreme caution and the use of SCBAs for protection should be considered. All air purifying respirators require a change schedule for cartridges or canisters not to exceed the maximum eight hour exposure covered by the AEGLs. A recent estimation of percutaneous absorption of nerve agent vapor suggests that a hazardous dose from skin absorption through airborne exposures is unlikely unless levels are significantly greater than the IDLH levels listed below. Skin protection at lower levels should be designed to prevent skin contact with liquid or contaminated surfaces. Nerve agents are toxic in small amounts on the skin and some can persist in the environment for days.
Summary of CDC and U.S. Army Airborne Exposure Limits
| Airborne Exposure Limits | Maximum Time of Exposure | Concentration of GA (mg/m3) |
Concentration of GB (mg/m3) |
Concentration of GD/GF (mg/m3) |
Concentration of VX (mg/m3) |
|---|---|---|---|---|---|
| IDLH (Immediately Dangerous to Life/Health) |
one time exposure | 0.1a,b | 0.1a,b | 0.05a,c | 0.003a,b |
| STEL (Short-Term Exposure Limit) |
15-minute exposure, limited to one occurrence per day | 0.0001a,b [1E-4] |
0.0001a,b [1E-4] |
0.00005a,c [5E-5] |
0.00001a,b [1E-5] |
| WPL (Worker Population Limit) |
Time-weighted average (TWA) for 8 hr/day, 5 days/wk | 0.00003a,b,c [3E-5] |
0.00003a,b [3E-5] |
0.00003a,c [3E-5] |
0.000001a,b [1E-6] |
| GPL (General Population Limit) |
Time-weighted average (TWA) for 24 hr/day, 7 days/wk, lifetime | 0.000001a,b [1E-6] |
0.000001a,b [1E-6] |
0.000001a,c [1E-6] |
0.0000006a,b [6E-7] |
| Percutaneous Vapor Toxicity Calculated Minimal Effect Values for 2 hour Exposure Period |
2.7 | 1.5 | 0.375 | 0.03 |
Personal Protective Equipment (PPE) Selection Guide for Emergency/
Accident Responses Based Upon EPA's Acute Exposure Guideline Levels
One Time Emergency Exposure Not to Exceed 8 hours Total
| Effects for Exposures Above AEGLs and PPE Guidance | Maximum Time of Exposure (one time exposure for emergency/accident response) |
Concentration of GA (mg/m3) |
Concentration of GB (mg/m3) |
Concentration of GD/GF (mg/m3) |
Concentration of VX (mg/m3) |
|---|---|---|---|---|---|
| AIR: Less than AEGL- 1 for stated duration times
No Respirator required. SKIN: Level D clothing if no splash or contact hazard. General washable work clothing or disposable coverall. Washable or disposable boots and gloves recommended for general purpose protection. If skin contact with liquid is a possibility, butyl rubber or layered impervious clothing which has received material and construction performance testing against specific chemical agents by the manufacturer, the government or a third party testing agency using an accepted protocol. |
10 MIN | 0.0069 | 0.0069 | 0.0035 | 0.00057 |
| 30 MIN | 0.0040 | 0.0040 | 0.0020 | 0.00033 | |
| 1 HR | 0.0028 | 0.0028 | 0.0014 | 0.00017 | |
| 4 HR | 0.0014 | 0.0014 | 0.00070 | 0.00010 | |
| 8 HR | 0.0010 | 0.0010 | 0.00050 | 0.000071 | |
| AIR: Less than 25 X 8 HR AEGL- 1
(a) Any CBRN-approved or CWA tested Powered Air Purifying Loose Fitting Facepiece, hood or helmet and a NIOSH-approved CBRN filter or a combination organic vapor, acid gas, particulate cartridge/filter. (b) Any CBRN-approved or CWA tested Continuous Flow respirator with a Loose Fitting Facepiece, hood or helmet. SKIN: Level D if no splash or contact hazard. General washable work clothing or disposable coverall. Washable or disposable boots and gloves recommended for general purpose protection. If skin contact with liquid a possibility boots and gloves mandatory, other chemical clothing based on hazard assessment. Butyl rubber or layered impervious clothing which has received material and construction performance testing against specific chemical agents by the manufacturer, the government or a third party testing agency using an accepted protocol. |
Maximum Time of Exposure (one time exposure for emergency/accident response) |
Concentration of GA (mg/m3) | Concentration of GB (mg/m3) | Concentration of GD/GF (mg/m3) | Concentration of VX (mg/m3) |
| 30 MIN | <0.1(IDLH) | <0.1(IDLH) | <0.05(IDLH) | <0.003(IDLH) | |
| 1 HR | <0.07 | <0.07 | <0.035 | <0.003(IDLH) | |
| 4 HR | <0.035 | <0.035 | <0.0175 | <0.0025 | |
| 8 HR | <0.025 | <0.025 | <0.0125 | <0.00178 | |
| AIR: Less than 50 X 8 HR AEGL- 1
(a) Any CBRN-approved or CWA tested Tight Fitting Air Purifying or Powered Air Purifying Full Facepiece. SKIN: Level D if no splash or contact hazard. General washable work clothing or disposable coverall. Washable or disposable boots and gloves recommended for general purpose protection. If skin contact with liquid a possibility boots and gloves mandatory, other chemical clothing based on hazard assessment. Butyl rubber or layered impervious clothing which has received material and construction performance testing against specific chemical agents by the manufacturer, the government or a third party testing agency using an accepted protocol. |
Maximum Time of Exposure (one time exposure for emergency/accident response) |
Concentration of GA (mg/m3 | Concentration of GB (mg/m3) | Concentration of GD/GF (mg/m3) | Concentration of VX (mg/m3) |
| 30 MIN | <0.1(IDLH) | <0.1(IDLH) | <0.05(IDLH) | <0.003(IDLH) | |
| 1 HR | <0.1(IDLH) | <0.1(IDLH) | <0.05(IDLH) | <0.003(IDLH) | |
| 4 HR | <0.07 | <0.07 | <0.035 | <0.003(IDLH) | |
| 8 HR | <0.050 | <0.05 | <0.025 | <0.003(IDLH) | |
| AIR: Greater than 50 X 8 HR AEGL- 1
(a) Any CBRN-approved or CWA tested Self Contained Breathing Apparatus a Full Facepiece operated in a Pressure Demand Mode. (b) Any CBRN-approved or CWA tested Supplied Air Respirator with a Full Facepiece operated in a Pressure Demand Mode with an Auxiliary Escape Bottle. SKIN: Level A/B. Level A if vapor concentration exceeds the levels listed above for percutaneous effects. Level A or B otherwise. Skin contact more likely with higher air levels. Butyl rubber or layered impervious clothing which has received material and construction performance testing against specific chemical agents by the manufacturer, the government or a third party testing agency using an accepted protocol. |
Maximum Time of Exposure (one time exposure for emergency/accident response) |
Concentration of GA (mg/m3) | Concentration of GB (mg/m3) | Concentration of GD/GF (mg/m3) | Concentration of VX (mg/m3) |
| 8 HR | >0.050 | >0.050 | >0.025 | >0.003(IDLH) |
References
a) Memorandum Subject: Implementation Guidance Policy for New Airborne Exposure Limits for GB, GA, GD, GF, VX, H, HD, and HT. Department of the Army OASA (I&E), (2004, June 18).
b) Final Recommendations for Protecting Human Health from Potential Adverse Effects of Exposure to Agents GA, GB, and VX. Department of Health and Human Services (DHHS), Centers for Disease Control and Prevention (CDC) Federal Register, Vol. 53, No. 50, p. 8504, (1988, March 15).
c) Memorandum Subject: Nerve Agent Percutaneous Exposure Criteria and Airborne Exposure Levels (AELs) for GD, GF in Use of Interim DA Guidance on Implementation of the New AELs. Department of the Army Office of the Surgeon General (2004, June 29).
Specific Hazard Information
Related Online Resources
NOTICE
This product is not a standard or regulation, and it has no effect on employers' legal obligations. The guidance is advisory in nature, informational in content, and is intended only as technical assistance to employers in providing a safe and healthful workplace during emergency response operations. This document does not enhance or diminish any existing obligations under the OSH Act. The information in this document is interim guidance only. It is anticipated that NIOSH CBRN approval for all classes of respirators will be available in the near future. This guidance will change at the time NIOSH CBRN certification standards are available for all respirator classes. OSHA also may update this guidance as additional information becomes available in the future.
Blister Agents
Introduction
Blister Agents or vesicants are chemicals which have severely irritating properties and can produce irritated and reddened skin with progression to blisters, swelling and inflammation of tissues surrounding the eyes with progression to light sensitivity and lacrimation. High concentrations of vapor or direct liquid exposures to the eye can cause damage to the eye surface. Warm, moist tissues are most susceptible to damage and the tissues of the upper respiratory tract can also be affected. Symptoms of exposure may be delayed until hours or days after exposure depending on the magnitude of the absorbed dose. The major chemical warfare agents in this category are sulfur mustard, nitrogen mustard and Lewisite.
Personal Protective Equipment
The recommendations for personal protective equipment (PPE) should be based on a site-based job hazard analysis of possible hazards including skin contact, air concentrations, heat stress, etc. All PPE should be used with appropriate additional administrative controls including medical surveillance, employee training, respirator fit-testing, and decontamination procedures to limit the potential for unforeseen adverse effects.
There are no current OSHA Permissible Exposure Limits (PELs) for exposure to blister agents. The National Research Council and EPA have published airborne limits to various agents called Acute Exposure Guideline Levels (AEGLs) to characterize the risk to the general population during a one-time accident and emergency scenario with time limits not to exceed 8 hours of exposure. For emergency responders and support personnel to a blister agent event, it seems appropriate to establish a target exposure limit at time weighted averages less than the lowest recommended AEGL-1 level for a given exposure duration. The AEGL-1 tier is the mildest effect category above which the general population, including susceptible individuals, could experience noticeable eye discomfort, irritation, or non-sensory effects. However, the effects are not disabling and are reversible upon cessation of exposure. The AEGL-1 and AEGL-2 values are based upon direct vapor exposure to the human eye and tissues surround the eye (conjunctiva), which are considered the most sensitive organ/tissue for blister agent vapor exposure effects by the National Research Council and the National Academy of Sciences. The CDC has made recommendations for worker exposure limits dealing with routine work processes such as demilitarization and transportation. Note: The CDC/NCEH worker exposure limits do not specifically include storage. These exposure standards may be substituted for work extending beyond the 8-hour AEGL limit if deemed appropriate after an incident.
The PPE ensemble selected depends on the level of knowledge available regarding the chemical agent. Respirators chosen initially for responders into a known release area should be a positive pressure self-contained breathing apparatus (SCBA) with a Level A protective suit until monitoring results allow for other decisions. OSHA would generally require these respirators to be NIOSH-certified CBRN SCBA respirators for use by employees. Some chemical warfare agents have been shown to seriously degrade and damage some respirators. Respiratory protection specifically approved by NIOSH for CBRN exposures is highly desirable but where not available, the incident commander may allow alternative suitable respirators during emergency operations. These are, depending on exposure levels, other NIOSH approved SCBAs or full-face air purifying respirators, which have been specifically tested by the manufacturer as effective against chemical warfare agents. Respirators other than SCBAs may be selected based upon accurate monitoring results with appropriate limits of detection for the subject agent. When conditions have been determined to be appropriate for the use of air purifying respirators, a NIOSH-approved CBRN APR Full Facepiece Air Purifying Respirator (APR) with a CBRN Canister, or a Chemical Warfare Agents (CWA) tested full facepiece APR with a combination organic vapor/acid gas/particulate canister may be used. A list of CBRN approved SCBA and APR may be obtained from the NIOSH website - APR or SCBA.
The requirements for skin protection from above the AEGL-1 but below the AEGL-2 should be focused initially on reducing the potential for contact with liquid agent residue. As airborne exposure rises above the AEGL-2 level, the potential for significant vapor absorption through the skin is possible and exposed skin should be minimized with the use of chemically protective clothing, preferably vapor tight encapsulating suits. Above AEGL-3, the incidence and severity of skin burns will increase and the use of encapsulating suits should be mandatory.
The tables below consolidate some information relating to AEGL exposure levels and the relative protection provided by certain types of respirators and clothing. These limits are for planning purposes and are not recommendations for particular work schedules. Any work schedules should be reviewed by a competent occupational health professional skilled in use of exposure limits and PPE. All air purifying respirators require a change schedule for cartridges or canisters not to exceed the maximum eight-hour exposure covered by the AEGLs.
Summary of CDC and U.S. Army Airborne Exposure Limits
| Airborne Exposure Limits | Maximum Time of Exposure | Concentration of Sulfur Mustard (HD) mg/m3 | Concentration of Lewisite (L) mg/m3 |
|---|---|---|---|
| IDLH (Immediately Dangerous to Life/Health) |
one time exposure | 0.7a,b | N/A |
| STEL (Short-Term Exposure Limit) |
15-minute exposure, limited to one occurrence per day | 0.003a,b [3E-3] |
N/A |
| WPL (Worker Population Limit) |
Time-weighted average (TWA) for 8 hr/day, 5 days/wk | 0.0004a,b [4E-4] |
0.003c,d |
| GPL (General Population Limit) |
Time-weighted average (TWA) for 24 hr/day,7 days/wk, lifetime | 0.00002a,b [2E-5] |
0.003c,d |
Personal Protective Equipment (PPE) Selection Guide for Emergency/
Accident Responses Based Upon EPA's Acute Exposure Guideline Levels
One Time Emergency Exposure Not to Exceed 8 hours Total
| Effects for Exposures Above AEGLs and PPE Guidance | Maximum Time of Exposure (one time exposure for emergency/accident response) |
Concentration of Sulfur Mustard (HD) mg/m3 | Concentration of Lewisite (L) mg/m3 |
|---|---|---|---|
|
Greater Than AEGL-1: Threshold for conjunctival injection and minor discomfort with no functional decrement in human volunteers. Respiratory: Any NIOSH CBRN approved or Chemical Warfare Agents (CWA) tested SCBA or a NIOSH-approved CBRN APR Full Facepiece Air Purifying Respirator (APR) with CBRN Canister, or a Chemical Warefare Agents (CWA) tested full facepiece APR with a combination organic vapor/acid gas/particulate canister. Skin protection: Protect against contact with liquid residues. Minimize exposed skin and protect high contact potential skin areas using gloves and boots. Butyl rubber or impervious construction are desirable. |
10 MIN | 0.40 | N/A |
| 30 MIN | 0.13 | N/A | |
| 1 HR | 0.067 | N/A | |
| 4 HR | 0.017 | N/A | |
| 8 HR | 0.0083 | N/A | |
|
Greater Than AEGL- 2: Threshold for well-marked generalized conjunctivitis, edema photophobia and eye irritation. Potentially impacting functional abilities or ability to escape; delayed recovery. Some studies indicate an increased potential for delayed skin burns from vapor exposure. Respiratory: Any NIOSH CBRN-approved or CWA tested SCBA or a NIOSH-approved CBRN APR Full Facepiece Air Purifying Respirator (APR) with a CBRN Canister, or a Chemical Warfare Agents (CWA) tested full facepiece APR with a combination organic vapor/acid gas/particulate canister. Skin Protection: An encapsulating Level A type suit which provides skin vapor protection constructed of butyl rubber or layered impervious clothing which has received material and construction testing against specific CBRN agents by the manufacturer, the government or a third party testing agency using an accepted protocol. The NFPA 1991 Standard on Vapor-Protective Ensembles for Hazardous Materials Emergencies and the NFPA 1994 Standard on protective Ensembles for Chemical/Biological Terrorism Incidents require mandatory testing against chemical warfare agents. |
10 MIN | 0.60 | N/A |
| 30 MIN | 0.20 | N/A | |
| 1 HR | 0.10 | N/A | |
| 4 HR | 0.025 | N/A | |
| 8 HR | 0.013 | N/A | |
|
Greater Than AEGL- 3 Life threatening; Threshold for sulfur mustard inhalation lethality in mice. Some studies indicate severe skin vesication from vapor exposure is likely above this level. Respiratory: Any NIOSH CBRN-approved or CWA tested SCBA. Skin Protection: An encapsulating Level A type suit which provides skin vapor protection. A butyl rubber or layered impervious clothing which has received material and construction testing against specific CBRN agents by the manufacturer, the government or a third party testing agency using an accepted protocol. The NFPA 1991 Standard on Vapor-Protective Ensembles for Hazardous Materials Emergencies requires mandatory testing against chemical warfare agents. |
10 MIN | 3.9 | N/A |
| 30 MIN | 2.7 | N/A | |
| 1 HR | 2.1 | N/A | |
| 4 HR | 0.53 | N/A | |
| 8 HR | 0.27 | N/A |
References
a) Memorandum Subject: Implementation Guidance Policy for New Airborne Exposure Limits for GB, GA, GD, GF, VX, H, HD, and HT. Department of the Army OASA (I&E), (2004, June 18).
b) Interim Recommendations for Airborne Exposure Limits for Chemical Warfare Agents H and HD (Sulfur Mustard). US Department of Health and Human Services (DHHS), Centers for Disease Control and Prevention (CDC) Federal Register, Vol. 69, No. 85, pp. 24164-2468, (2004, May 3).
c) Final Recommendations for Protecting Human Health and Safety Against Potential Adverse Effects of Long-term Exposure to Low Doses of Agents GA, GB, VX, Mustard Agent (H, HD, T), and Lewisite (L). US Department of Health and Human Services (DHHS), Centers for Disease Control (CDC) Federal Register, Vol. 53, No. 50, p. 8504, (1988, March 15).
d) AR 385-61: The Army Chemical Agent Safety Program. US Department of the Army, (2001, October 12).
e) CSEPP Policy Paper Number 20 (Revised): Adoption of Acute Exposure Guideline Levels (AEGLs). Chemical Stockpile Emergency Preparedness Program, Federal Emergency Management Agency and Department of the Army, (February, 2003).
f) CSEPP Planning Guidance (Draft). Chemical Stockpile Emergency Preparedness Program (CSEPP) Steering Committee, Federal Emergency Management Agency (FEMA), Washington, DC (IEM/TEC05-005, June 2005).
g) Evaluation of Chemical WarfareAgent Percutaneous Vapor Toxicity: Derivation of Toxicity Guidelines for Assessing Chemical Protective Ensembles. Oak Ridge National Laboratory Technical Memo ORNL/TM-2003/180. Oak Ridge National Laboratory, Oak Ridge, TN, (2003, July).
h) Acute Exposure Guideline Levels for Selected Airborne chemicals, Vol 3. "Nerve Agents GA, GB, GD, GF, and VX" pp.15-300; "Sulfur Mustard (Agent HD)," pp, 301-383. National Research Council Committee on Toxicology Subcommittee on Acute Exposure Guideline Levels. National Academy Press, Washington, DC, (2003).
i) Standing Operating Procedures for Developing Acute Exposure Guideline Levels for Hazardous Chemicals. National Research Council Committee on Toxicology Subcommittee on Acute Exposure Guideline Levels. National Academy Press, Washington, DC, (2001).
j) Veterans at Risk: The Health Effects of Mustard Gas and Lewisite. National Academy of Sciences, Institute of Medicine, Committee to Survey the Health Effects of Mustard Gas and Lewisite. National Academy Press, Washington, DC., (1993).
k) Review of Acute Human-Toxicity Estimates fro Selected Chemical-Warfare Agents. National Research Council Committee on Toxicology Subcommittee on Toxicity Values for Selected Nerve and Vesicant Agents. National Academy Press, Washington, DC, (1997).
Specific Hazard Information
Related Online Resources
NOTICE
This product is not a standard or regulation, and it has no effect on employers' legal obligations. The guidance is advisory in nature, informational in content, and is intended only as technical assistance to employers in providing a safe and healthful workplace during emergency response operations. This document does not enhance or diminish any existing obligations under the OSH Act. The information in this document is interim guidance only. It is anticipated that NIOSH CBRN approval for all classes of respirators will be available in the near future. This guidance will change at the time NIOSH CBRN certification standards are available for all respirator classes. OSHA also may update this guidance as additional information becomes available in the future.
Radiological Dispersal Devices
A Radiological Dispersal Device (RDD), or "Dirty Bomb", is a conventional explosive device which has been surrounded with or contaminated with some form of radioactive material. When it explodes, the device spreads the radioactive material over a wide area. The purpose of these devices is to frighten people and make buildings and land unusable during the weeks necessary to perform decontamination. In the most likely scenario, low-level radioactive powder or pellets would be used, and the contamination would be dispersed over a few city blocks. The actual radiation hazard would be dependant on the source material used. It is not likely that enough radiation would be present to cause severe illness in the exposed population.
Emergency responders to an explosion or the resulting fires will generally not know they are being exposed to radiation unless they utilize a radiation detecting device. There is no practical personal protective equipment (PPE) to protect First Responders against externally penetrating gamma radiation. Monitoring devices are the only means to ensure that responders do not enter an area where exposures to external gamma radiation is excessive.
Personal protective equipment (PPE) to prevent skin contamination of particulates is very effective against particulate-borne radiation hazards (i.e., alpha and beta particles). Typical fire fighter "turn-out" gear, including a SCBA, is generally adequate for this purpose. The use of turn-out gear or any disposable protective clothing suitable for particulate exposure, should be followed by appropriate decontamination of personnel and equipment.
Protection of internal organs from inhalation of radioactive particulates can be provided by wearing an appropriate particulate respirator. The SCBAs will provide the highest level of protection. Responders should utilize at least a full-face air-purifying respirator with a P-100 or HEPA filter, as appropriate. Respiratory protection specifically approved by NIOSH for CBRN exposures is desirable. However, where specific CBRN-approved respirators are not available, the incident commander may allow alternative NIOSH-approved respirators, such as SCBAs, or full-face powered or non-powered air-purifying respirators with P-100 or HEPA filters, as appropriate. It should be noted that these recommendations for respiratory protection are designed ONLY for protection against inhalation of radioactive particulates, and do not consider protection that may be necessary for other contaminants, such as chemical or biological agents.
Particulate sampling can be performed to measure the radioactivity of dust in the air and to further characterize exposures. Based on the sampling data, the respirator protection factor needed to meet the relevant exposure limits can be determined (see table below), and the specific type of respirator needed can be identified. According to the data, it may be possible to downgrade or remove requirements for respiratory protection. However, until exposures have been characterized, responders and support personnel should continue to utilize full-face air-purifying P100 respirators, or higher respiratory protection (e.g., SCBAs, PAPRs).
Guidance Matrix for RDD Incidents
|
OSHA Occupational Exposure Limits for Ionizing Radiation 29 CFR 1910.1096 |
Rems per calendar quarter |
|---|---|
|
Whole Body; Head and Trunk; Active Blood-Forming Organs; Lens of Eye or Gonads |
1 1/4 |
|
Hands and Forearms; Feet and Ankles |
18 3/4 |
|
Skin of Whole Body |
7 1/2 |
|
Under age 18 workers |
10 percent of above limits |
|
Over age 18 workers |
3 rem may be permitted under conditions specified in 29 CFR 1910.1096(b)(2) |
Note: The Department of Homeland Security is currently chairing an interagency workgroup which is in the process of assessing the protective action guidance for response to an RDD event.
References
- 29 CFR 1910.1096, Ionizing Radiation. OSHA Standard.
- Manual of Protective Action Guides and Protective Actions for Nuclear Incidents. Environmental Protection Agency (EPA), Office of Radiation Programs, (May 1992).
- Radiological Emergency Response Health and Safety Manual. U.S. Department of Energy (DOE) Report DOE/NV/11718-440, (May 2001).
Specific Hazard Information
Related Online Resources
- General References
- Ionizing Radiation. OSHA Safety and Health Topics Page.
NOTICE
This product is not a standard or regulation, and it has no effect on employers' legal obligations. The guidance is advisory in nature, informational in content, and is intended only as technical assistance to employers in providing a safe and healthful workplace during emergency response operations. This document does not enhance or diminish any existing obligations under the OSH Act. The information in this document is interim guidance only. It is anticipated that NIOSH CBRN approval for all classes of respirators will be available in the near future. This guidance will change at the time NIOSH CBRN certification standards are available for all respirator classes. OSHA also may update this guidance as additional information becomes available in the future.
General References
Additional OSHA Resources
- Related Safety and Health Topics Pages
Other Government Websites
- Department of Homeland Security (DHS)
- Federal Emergency Management Agency (FEMA)
- DisasterAssistance.gov. This Disaster Management e-Government Initiative focuses on providing information and services relating to the four pillars of all-hazards disaster management: preparedness, response, recovery, and mitigation.
- Ready.gov. A site to help Americans learn about and prepare for potential terrorist attacks (Biological, Chemical, Explosions, Nuclear Blast, Radiation).
- U.S. Environmental Protection Agency (EPA) - Chemical Emergency Preparedness and Prevention Advisories. Includes information regarding Chemical Emergency Preparedness.
- Centers for Disease Control and Prevention (CDC). Emergency Preparedness and Response.
- National Institute for Occupational Safety and Health. Emergency Response Resources.
- USAMRIID. U.S. Army Medical Research Institute of Infectious Diseases.
Standards/Exposure Guidelines
- Memorandum Subject: Nerve Agent Percutaneous Exposure Criteria and Airborne Exposure Levels (AELs) for GD, GF in Use of Interim DA Guidance on Implementation of the New AELs. Department of the Army Office of the Surgeon General, (June 29, 2004).
- Memorandum Subject: Implementation Guidance Policy for New Airborne Exposure Limits for GB, GA, GD, GF, VX, H, HD, and HT. Department of the Army OASA (I&E), (June 18, 2004).
- Interim Recommendations for Airborne Exposure Limits for Chemical Warfare Agents H and HD (Sulfur Mustard). Department of Health and Human Services (DHHS), Centers for Disease Control and Prevention (CDC) Federal Register, Vol. 69, No. 85, pp. 24164-2468, (May 3, 2004).
- Final Recommendations for Protecting Human Health from Potential Adverse Effects of Exposure to Agents GA, GB, and VX. Department of Health and Human Services (DHHS), Centers for Disease Control and Prevention (CDC) Federal Register, Vol. 68, No. 196, pp. 58348-58351, (October 9, 2003).
- Toxicological Profile for Sulfur Mustard. Agency for Toxic Substances and Disease Registry (ATSDR), (September 2003).
- CDC Proposed Airborne Exposure Limits for Chemical Warfare Agents (H, HD, HT). Centers for Disease Control and Prevention (CDC) Federal Register Vol. 68, No. 140, (July 22, 2003).
- ToxFAQs™ for Nerve Agents (GA, GB, GD, VX). Agency for Toxic Substances and Disease Registry (ATSDR), (April 2002).
- ToxFAQs™ for Sulfur Mustard. Agency for Toxic Substances and Disease Registry (ATSDR), (April 2002).
- ToxFAQs™ for Blister Agents: Lewisite (L), Mustard-Lewisite Mixture (HL). Agency for Toxic Substances and Disease Registry (ATSDR), (April 2002).
- ToxFAQs™ for Blister Agents: HN-1, HN-2, HN-3 (Nitrogen Mustards). Agency for Toxic Substances and Disease Registry (ATSDR), (April 2002).
- ToxFAQs™ for Blister Agents: Sulfur Mustard Agent H/HD, Sulfur Mustard Agent HT. Agency for Toxic Substances and Disease Registry (ATSDR), (April 2002).
- Toxic Chemical Agent Safety Standards. Department of the Army Pamphlet 385-61, (November 13, 2012).
- EPA Acute Exposure Guideline Levels (AEGLs) Nerve Agents Exposure Values. Environmental Protection Agency (EPA) Federal Register Vol. 66, No. 85, (May 2, 2001).
- Review of Acute Human-Toxicity Estimates for Selected Chemical-Warfare Agents. The National Academies Press, (1997).
- Emergency Response to Incidents Involving Chemical and Biological Warfare Agents. National Fire Protection Association (NFPA) Supplement 14, (1997).
- Final Recommendations for Protecting Human Health and Safety Against Potential Adverse Effects of Long-term Exposure to Low Doses of Agents GA, GB, VX, Mustard Agent (H, HD, T), and Lewisite (L). U.S. Department of Health and Human Services (DHHS), Centers for Disease Control (CDC) Federal Register, Vol. 53, No. 50, p. 8504, (March 15, 1988).
- Recommendations for Protecting Human Health Against Potential Adverse Effects of Long-Term Exposure to Low Doses of Chemical Warfare Agents. Centers for Disease Control and Prevention (CDC), Morbidity and Mortality Weekly Report 37(5):72-4, 79, (February 12, 1988).
PPE (General)
- Standards for Personal Protective Gear for First Responders. Department of Homeland Security (DHS).
- Guide for the Selection of Personal Protection Equipment for Emergency First Responders. National Institute of Justice Guide 102-00 (Volumes I), (November 2002).
- Standard on Protective Ensembles for Chemical/Biological Terrorism Incidents. National Fire Protection Association, (2001).
NIOSH CBRN Certification
- National Personal Protective Technology Laboratory (NPPTL)
- Chemical and Biological Respiratory Protection Workshop Report. U.S. Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 2000-122, (February 2000).
Specific Hazard Information
NOTICE
This product is not a standard or regulation, and it has no effect on employers' legal obligations. The guidance is advisory in nature, informational in content, and is intended only as technical assistance to employers in providing a safe and healthful workplace during emergency response operations. This document does not enhance or diminish any existing obligations under the OSH Act. The information in this document is interim guidance only. It is anticipated that NIOSH CBRN approval for all classes of respirators will be available in the near future. This guidance will change at the time NIOSH CBRN certification standards are available for all respirator classes. OSHA also may update this guidance as additional information becomes available in the future.