by Eileen Senn, MS

OSHA and NIOSH have now officially recommended the use of respirators by the offshore Gulf cleanup workers closest to the crude oil, including those drilling relief wells, applying dispersant, and providing support and supplies. While respirators are not generally recommended for onshore and nearshore workers, there are exceptions for workers if they are near to or downwind of burning oil, far from shore, performing high pressure washing, cleaning fresh crude oil from wildlife, or experiencing symptoms or health problems. Recommendations are also given for the care of disposable respirators and the voluntary use of respirators.

The long-awaited recommendations are contained in the 18-page NIOSH/OSHA Joint Interim Guidance for Protecting Deepwater Horizon Response Workers and Volunteers. The document addresses health effects from crude oil and dispersants, as well as guidance about conducting exposure assessments, medical evaluation and care, selecting personal protective equipment, and preventing heat stress, fatigue, and traumatic incidents. Appendix A of the document summarizes the findings of studies from selected oil tanker spill disasters on human health effects.

The NIOSH/OSHA recommendations were issued June 25, 2010, almost ten weeks after the April 20 start of the spill and cleanup. Before then, OSHA repeatedly stated that respirators were not needed onshore or on nearshore vessels, based on their air sampling, most of which has failed to find detectable levels of chemicals in the Gulf air. One limitation of OSHA’s assessment, however, was that the agency conducted no air sampling offshore because authority offshore falls under the Coast Guard.

OSHA maintained their “no respirators needed” position despite the fact that both they and NIOSH have online access to daily updates of complete BP worker air sampling data. The sporadic and limited public summaries of the BP data available to the rest of us have shown many more exposures of concern than suggested by the OSHA sampling data. Inexplicably, neither OSHA nor NIOSH have publicly discussed the BP data. I wrote previously on my assessment of BP’s summary data.

The inadequacy of the number of chemicals being monitored by BP and OSHA became clearer with the issuance of on June 23 of NIOSH’s Interim Health Hazard Evaluation (HHE) Report. On June 4 and 5, NIOSH conducted air sampling on a vessel applying dispersant. They detected 16 of the 20 chemicals for which they sampled: acetone, acrolein, benzene, 2-butoxy ethanol, carbon monoxide, diesel exhaust as elemental carbon, ethyl benzene, ethanol, isopropyl alcohol, limonene, naphthalene, dipropylene glycol butyl ether, propylene glycol, toluene, total hydrocarbons as hexane, and xylenes.

Simple comparisons with established exposure limits for single substances don’t show a problem, usually by orders of magnitude. The highest concentrations relative to exposure limits were for acrolein, benzene, and ethanol. On an additive basis, for any given exposure period, the mixtures of chemicals measured in the air were less than 10% of the acceptable levels. Although it is the most extensive exposure assessment to date in the Gulf, in many ways the HHE report is a “Clean Bill of Health,” a characterization that doesn’t reflect accurately the complexity of the hazards to which workers are exposed. There are no exposure limits established to evaluate the mix of toxic compounds and physical stressors experienced by these workers.

It remains to be seen if the NIOSH/OSHA recommendations will translate into more Gulf workers receiving respirators. The biggest opportunity lies in the recommendation that respirators be supplied for “uncharacterized” chemical exposures. I believe that most exposures in the Gulf are uncharacterized because they are to mixtures of mixtures that have not been adequately assessed either qualitatively or quantitatively. If NIOSH and OSHA are serious about this recommendation, many workers will receive respirators.

Most other respirators recommendations are rather technical and dependent on exposure assessment, air sampling, and expert professional judgment. Some recommendations depend on workers reporting symptoms or health problems. Few cleanup workers may dare to do that or to ask for a respirator, fearing retaliation.

The recommendations do not define the term “excessive exposure” although the term is used in the recommendations related to the offshore workers who may have the greatest likelihood of chemical exposures. No listing of recommended exposure limits is given nor advice for dealing with chemicals without appropriate exposure limits, for example, total hydrocarbon vapors and crude or weathered oil mist, or for evaluating exposure to complex mixtures. On a positive note, cautions are given to downwardly adjust exposure limits when work exceeds 40 hours a week. And the recommendations do a good job describing a comprehensive exposure assessment as

“evaluation of multiple different work settings, each with its own set of exposure variables. These work settings involve changing weather conditions, various types and amounts of VOCs being released, work tasks resulting in potential skin and inhalational exposures, and exposure to wildlife and physical hazards, such as heat, snakes and insects. In addition, response workers and volunteers are engaging in activities that may be unfamiliar, thus increasing the potential for injury or exposure.”

With the issuance of the recommendations, some of the obstacles to providing workers with respirators seem to be loosening their grip, but they have certainly not completely disappeared. As I describe in my June 19 post they include:

*Lack of focus on the adverse health effects of airborne contaminants
*Limited air sampling
*Outdated exposure limits
*Oil company protocols for limiting respirator use
*Concerns that respirators will worsen heat stress to workers
*OSHA requirements for respirator use

BP Sampling and Respirator Protocols Unchallenged

The NIOSH/OSHA recommendations do not address whether or not air sampling and respirator protocols that BP already has in place comply with their recommendations. These protocols have been in effect for many weeks and severely limit the use of respirators offshore and onshore and nearshore.

I critiqued the respirator aspects of the BP offshore plan in my June 19 post. On June 11, BP added area sampling for particulate matter and sulfur dioxide as respirator triggers.

The biggest problems with the BP protocols are that too few chemicals are measured and the trigger levels for donning respirators are too high. For example, respirator use of VOCs, which have no applicable exposure limit, is triggered at 100 ppm offshore and 50 ppm onshore and nearshore. For benzene, the trigger in all areas is 0.5 ppm, five times the NIOSH Recommended Exposure Limit (REL) of 0.1 ppm.

Data for these triggers come not from personal sampling but from area sampling with direct reading instruments. The onshore/nearshore protocol states that Photo Ionization Detectors (PIDs are calibrated by the Center for Toxicology and Environmental Health (CTEH), which has recently come under scrutiny for inaccurate monitoring procedures.

As indicated by the BP offshore protocol, no personal sampling is conducted in offshore areas. The BP onshore/nearshore protocol, describes personal sampling or benzene, toluene, xylene, and total hydrocarbons using 3M 3500 Organic Vapor Monitors. A reading of the technical data for these monitors reveals recommended sampling times of 8 hours plus time for analysis, so they are useless for triggering respirator use. This would seem to make moot the respirator triggers of 100 ppm for xylene and toluene given in the onshore/nearshore protocol. For toluene, this trigger is five times the ACGIH Threshold Limit Value (TLV) of 20 ppm.

Hopefully, NIOSH and OSHA will continue to refine their respirator recommendations to address omissions and require BP and contractors to comply with them.

Eileen Senn is an industrial hygienist who has performed occupational health work for government and unions for 40 years. She was an OSHA industrial hygiene inspector in Philadelphia for eight years in the 70s and 80s. She directed an OSHA New Directions training grant from 1979 to 1981. She worked in occupational health surveillance for the state of New Jersey from 1986 to 2002. She has been an Independent consultant for the past eight years. She is perhaps best known for her seminal article, Playing Industrial Hygiene to Win.

Note: Text of OSHA/NIOSH Respirator Recommendations
Note: Page numbers refer to the pdf version of the recommendations. Read the recommendations in their entirety for footnotes and context on exposure assessment, air sampling, and additional controls and personal protective equipment recommended.

Uncharacterized Chemical Exposures: Respiratory protection precautions are necessary for uncharacterized chemical exposures until the need for such precautions has been ruled out by comprehensive assessment of exposures to toxic chemical agents during work activities under a variety of relevant conditions. (Bottom of page 3, top of page 4)

Disposable Respirators: Given the warm and humid conditions existing during the Deepwater Horizon Response, disposable filtering facepiece respirators will likely need to be discarded after several hours of use, in part because they will become moist with perspiration. These respirators should be discarded and replaced if they are soaked, contaminated, damaged, or hard to breathe through. For intermittent use of disposable filtering facepiece respirators, they may be stored in a clean, breathable container, such as a paper bag between uses. Disposable filtering facepiece respirators must be used only by a single wearer. Elastomeric respirators can be cleaned, disinfected and reused. Specific information on cleaning re-usable respirators can be found in the OSHA Respiratory Protection Standard. (Top of page 9)

General Guidance: A decision to use respiratory protection should be based on the best available qualitative information using the expert opinion method and on the best available comprehensive quantitative information about the type and level of exposure to toxic chemical and physical agents by the inhalational route. The use of effective engineering and administrative controls, and other personal protective equipment should be implemented before the use of respirators for worker protection is considered. (Middle of page 9)

Source Control Activities: For workers involved in source control activities, respirators should be used in those situations where potentially excessive exposure is reasonably anticipated or where indicated by exposure assessment or where symptoms/health effects are being reported. Where eye protection is not needed against irritating gases/vapors, NIOSH and OSHA recommend using a half facepiece respirator. If eye protection is needed, NIOSH and OSHA recommend a full facepiece elastomeric respirator with an organic vapor/P100 cartridge. A full facepiece respirator provides eye protection against irritating gases/vapors and a relatively high level of respiratory protection when exposures are variable and potentially higher. Cartridges including P100 particulate filters (oil resistant) are recommended over N95 filters (not resistant to oil aerosols). The combination organic vapor/P100 cartridge provides comprehensive protection against both particulates and gases and vapors, and the P100 filter provides some protection against water mist for the organic vapor filter component. (Bottom of page 9, top of page 10)

Vessels Involved in Burning Crude Oil: Under ideal conditions, vessels will be located a sufficient distance upwind from burns, and respiratory protection may not be necessary. The employer should assess the specific job tasks before the burning activity to evaluate potential worker exposures and then select respiratory protection and other PPE according to the results of their evaluation. Respiratory protection will be needed, however, when shifts in wind cause exposure to the combustion products in the plume. Under such circumstances, or where symptoms/health effects are being reported, inhalational exposure may occur and NIOSH and OSHA recommend respiratory and eye protection.

For unexpected exposures, protection can be provided by use of a full facepiece elastomeric respirator with an organic vapor/P100 cartridge. A full facepiece respirator is preferred because it provides both eye protection against irritating smoke and an appropriate level of respiratory protection. Cartridges including P100 particulate filters (oil resistant) are recommended over N95 filters (not resistant to oil aerosols). The combination organic vapor/P100 cartridge provides comprehensive protection against soot, gases and vapors. Another means of protection is non-vented safety goggles to prevent eye irritation and a half-mask respirator with an organic vapor/P100 cartridge. (Middle of page 10)

Vessels Not Involved in Source Control or Burning: Some vessels operating off-shore engage in deployment of containment and sorbent booms, skimming operations to remove oil from the water and dispersant application. These vessels are not involved in burning nor are they located in close proximity to in-situ burning. Generally, these vessels have contact with oil that has weathered, and, as such, does not emit significant amounts of VOCs. Respiratory protection generally will not be necessary as symptoms/health effects are not expected to occur in this setting. Dermal protection is needed.

Other vessels not involved in burning may operate at a farther distance from shore and possibly encounter more volatile crude. In this case, administrative controls (e.g., worker rotation and decrease in work hours) and respiratory protection (e.g., half-mask elastomeric respirator with an organic vapor cartridge) should be implemented where symptoms/health effects are being reported. (Top of page 11)

Shoreline Clean-up Activities: Since inhalational exposure to oil and dispersants during shoreline clean-up operations is low because of weathering, respiratory protection is not recommended. However, if symptoms/health effects occur, the affected worker(s) should be removed and evaluated medically, and then the worksite should be assessed for potential exposure to heat and VOCs for the remaining workers. Note: If high pressure washing is conducted, aerosolization of oil mist into respirable droplets could occur and respiratory protection is recommended with use of at least the level of a disposable P100 filtering facepiece respirator. The use of highly concentrated detergents, degreasers, and solvents, and the use of heated water during pressure washing, may volatilize hydrocarbons and result in the need for respiratory protection. Respiratory protection, if deemed necessary by professional judgment and/or air monitoring results, should include the use of a combination organic vapor/P100 cartridge half mask respirator. Eye and skin protection during such activities also will be necessary. (Middle of page 11)

Decontamination Activities: Vessels, PPE and other equipment may become contaminated with weathered oil. Respiratory protection is generally not necessary for this activity, although other PPE, including dermal, eye, face protection and protective footwear is necessary. If a high pressure washing mechanical sprayer is used to decontaminate PPE and other equipment, respirable particle aerosolization of oil mist could occur. When there is potential exposure to oil mist, particulate respiratory protection of at least the level of a P100 disposable filtering facepiece respirator is recommended in addition to skin, eye, face protection and protection footwear, particularly if highly concentrated detergents, solvents or degreasers are used. (Bottom of page 11)

Cleaning Wildlife: Respiratory protection is not generally recommended, unless wildlife is heavily coated with fresh crude oil. In such cases, a half mask respirator with an organic vapor cartridge is recommended. (Top of page 12)

Voluntary Use of Respirators: Even when comprehensive and routine air monitoring indicates that no inhalational hazard exists, an employer may permit respiratory protection to be worn voluntarily by employees provided it will not in itself create a hazard. See the OSHA Respiratory Protection Standard (29 CFR Section 1910.134). The Interim Guidance makes clear those exposure situations where the use of respiratory protection is recommended (see Section IX.C.1. through 5.)

The only situation where voluntary use may be helpful is when an individual is bothered by non-hazardous levels of hydrocarbon odor and cannot be relocated to another work area. In that case, a carbon-impregnated odor-reduction filtering facepiece respirator may provide some odor reduction potential–and can be worn voluntarily without the employer having to implement a respiratory protection program. These types of respirators do not provide health protective effects; they only provide odor reduction. In addition, all respirators have adverse effects on breathing, vision and communication, result in some discomfort, and are associated with additional physiological stress.

Employers or volunteer organizations who supply respirators for voluntary use must provide response workers with the information in Appendix D (Information for Employees Using Respirators When Not Required by the Standard) of the OSHA Respiratory Protection Standard, 29 CFR Section 1910.134.


  1. #1 Art
    July 2, 2010

    As a Florida resident who has worked construction I think you have to be aware that most respirators are miserable to wear in heat and humidity. The last thing anyone wants is to place a hunk of plastic over your face when you are sweating.

    For working in heat and humidity disposable filter masks are much more comfortable if they have an exhalation valve. They may also last longer because they are not wet so quickly with moisture from the breath and they may improve protection because people wearing them are less likely to remove them frequently to avoid the suffocating feelings of re-breathing your own breath.

    Full-face respirators are best if they are powered faceplate and hood type. These are positive pressure units hose fed from a belt-hung battery and filtration unit, They do not require a tight seal around the face. Wearing one feels very much like wearing a simple plastic face shield with a good breeze coming in and carrying off your exhalations. Comfort and cooling are greatly improved over half or full-masks that rely on a tight seal around the face and rely on breath action to move air.

    In confined spaces, extreme heat and high concentrations of contaminates good use can be made of compressor-fed, vortex cooled, hoods, helmets and mantlets. These are common industrial units often seen around shipyards and used to protect operators who are sandblasting, welding or spray painting. Place the operator in a temperature controlled and mechanically ventilated space inside a hood or suit. It requires that they trail a compressed air line but the interior conditions are quite comfortable.

    Temperatures on the gulf are going to stay in the mid 80s to high-90s. Humidity can be expected to hover around 80 to 100%. The heat index will hover around 100F or higher for much of the day. If respirators are called for some effort will have to be made to get ones that are usable under those conditions.

  2. #2 Eileen Senn
    July 2, 2010

    Thank you for your great comments, Art. Yes, heat is a problem that must be addressed, I discuss how in my July 18 post and the NIOSH/OSHA recommendations do so also. You are absolutely correct that some types of respirators put less strain on the heart and lungs and are therefore easier to wear in the heat.

  3. #3 Scott
    July 6, 2010

    Thanks for your post Eileen. My question is who exactly needs to wear respirators? You make it sound as though everyone in the Gulf should be wearing them. I don’t believe that is the case. So if everyone doesn’t5 need them, how should one decide when use should be required? It seems there are only three reasonable criteria that can be use: 1) air sampling data- if levels are high as compared to the most protective OELs then use should be required for those workers. If levels are low, thenh we look to other data. 2) Professional judgement- a professional IH can look at an operation and determine that a worker may be at risk of high exposures, despite air sampling data showing low levels, based on the type of operation and tasks being done. 3) Illness data- where workers are getting respiratory illnesses you could logically conclude that those workers and others doing those tasks might be at risk. Absent those three criteria, I don’t see the need to require respirator use. If you have any other more meaningful criteria to use, I would love to see them. Otherwise, please tell us what you would use to determine who should be required to wear respirators and who shouldn’t. Thus far the sampling data have shown very low levels of exposure, particularly for shore workers. IHs from NIOSH and OSHA are characterizing potential exposures from the 16 identified tasks. The illness data show very few workers being treated for respiratory illnesses, other than those with preexisting respiratory illnesses like asthma. Most medical treatment has been first aid or treatment for heat stress (aside form those ship workers who were exposed to cleaning solvents). So I think the OSHA/NIOSDH recommendations flow logically from the data which exist. If you think otherwise, who would you require to wear respirators and using what criteria?

  4. #4 Eileen Senn
    July 6, 2010

    Thank you for asking about which Gulf workers I believe should receive respirators, Scott. To set the record straight, I don’t believe that every cleanup worker in the Gulf needs a respirator.

    Gulf clean-up workers are potentially exposed to a complex mixture of toxic chemicals, numbering over 50 and perhaps in the hundreds. The scientific community lacks complete information on either the short-term or long-term health effects of this mixture. Only a very few of these chemicals are being sampled in the Gulf air, yet life and death decisions about who gets respirators are being made based on air sampling data. We need to know which of these chemicals have been selected for sampling and why.

    Worker exposures in the Gulf change depending on how near they are to the oil leak, burning oil, dispersant applications from air and sea, other detergents and cleaning chemicals in use. Wind direction, wave action, cleanup tasks being performed, and equipment being used also influence exposures. OSHA and public BP sampling results are being reported without noting exactly where samples were collected and these other variables. I am not convinced that worst case exposures have been captured for the 37,000 cleanup workers including those on 6,500 vessels in an area one-third the size of Texas and on hundreds of miles of coastline.

    As discussed in my June 11 post, even the limited sampling that has been done by BP shows levels of enough concern to warrant the use of respirators for some workers. Inexplicably, neither OSHA nor NIOSH have publicly discussed the BP data although they have real time access to current and complete data. The rest of us are dependent on brief summaries, the last posted by BP June 9, over three weeks ago.

    I believe that NIOSH/OSHA respirator recommendations are too restrictive and easily undermined since they depend on the judgment of professionals who may or may not be available and impartial, air sampling that is woefully inadequate, and worker health complaints, which are surely underreported. A fourth criteria is needed – a rigorous qualitative exposure assessment describing all the chemicals of concern and their health effects.

    Respirators should be selected by an expert team based on such a rigorous qualitative exposure assessment for specific clean-up tasks and equipment in specific locations on rigs, offshore, nearshore, in marshes, and on beaches. The selections should be made into a set of standard respirator recommendations that cannot be easily undermined. Air sampling should inform the selections but should not dominate them. Recommendations should not be dependent on onsite professional judgment or worker health complaints.

    In addition, any other Gulf clenaup worker who wants a respirator should be able to ask for and receive an appropriate one – without saying why they want it and without fear of retribution.

  5. #5 Chris Whitside
    July 6, 2010

    Great to finally find some sensible information on the toxic air situation in the Gulf. Good work.

    Riki Ott ( and, a marine toxicologist and veteran of the Exxon Valdez is taking a long-term view of the threat to workers and regional residents. She notes that mortality due to upper respiratory disease amongst Valdez cleanup crews has been extremely high since that spill in 1989.

    Your comments about requiring respirators or not seem to be based on short-term industrial practice, and from that perspective are probably quite valid for clean-up crews. The big challenge though is to look at the issue over the long term. What happens if the oil vapor hangs in the air for months … or even years and spreads widely? Wearing respirators starts to make sense for cumulative exposure.

    And what about the other gases: benzene, hydrogen sulphide, etc.? Is there anything to the alarmist claims of Lindsey Williams?

  6. #6 Eieen Senn
    July 7, 2010

    Thank you. Chris.

    I agree Riki Ott is doing much-needed work in the Gulf spill. She is one of the few voices saying what a public health and occupational health tragedy the spill and its cleanup are.

    I haven’t thought much about the long-term impact of the spill, having focused my energy on immediate preventive measures. Long-term contamination of the soil and water, and perhaps even the air, seems certain. And that means contamination of all living things that stay in the area.

    I don’t know enough to comment on Lindsey Williams’s claims about the oil being leaked being a different, more toxic type – abiotic of non-fossil origin – because of the depth of the well.

    I do know that the MSDS provided by BP on the crude oil on pages 23 to 33 of their onshore/nearshore monitoring strategy is totally inadequate. It lists only three ingredients – benzene, hydrogen sulfide, and PAHs. I am currently compiling a list of chemicals potentially in the air in the Gulf and am over 50 from the crude alone.

    To see the MSDS, go to their monitoring strategy document.

  7. #7 Sott
    July 8, 2010

    NIOSH is doing a rigorous tox analysis of the oil and other chemicals. The fourth criteria you propose is flawed. You have to look not only at the toxicology but also the exposure potential. OSHA and NIOSH are collaborating on characterizing each of the major tasks. I believe this will result in rational assessments of when respirator use is actually needed.

  8. #8 Eileen Senn
    July 8, 2010

    I agree that qualitative exposure assessments must look at both the toxicology and the exposure potential and I think that was clear in my response.

    I’m glad to hear that NIOSH is analyzing the oil and other chemicals. Unfortunately, it’s pretty late in the game for workers who have been breathing them for 11 weeks now. I’m sure the analyses will be useful when the epidemiology studies are being done. Meanwhile, while chemicals and exposures are still being characterized, workers need to be proactively protected.

  9. #9 OSHA Guy
    November 15, 2010


    I think you bring up a good point! It IS great that NIOSH is analyzing the oil and chemical risk, but it is very late in the game. Why should it take 11 weeks for them to issue a “recommendation”? It’s like Franklin said, “An ounce of prevention is better than a pound of cure.”

  10. #10 Mendel Potok
    February 3, 2011

    I think it goes without saying that the workers need adequate surface protection, that’s true in any chemical disaster. However, dispersant of this magnitude of use has never been remotely done before, and measuring it’s effect would be just as effective with 4 weeks of exposure to 11 weeks. What is begin measured here is the chemical’s effect over time, and it is only then that if medical complications occur they can know what to do about it.