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.