Draft Risk Evaluation for Fuel Additive Considers Inhalation, Dermal Exposures

EPA’s draft risk evaluation for ethylene dibromide, released earlier this week, states that the fuel additive presents “unreasonable risk to workers and occupational non-users driven by inhalation and dermal exposures under multiple conditions of use.” EPA notes that ethylene dibromide’s primary use is as a lead scavenger in commercial and consumer leaded aviation fuel to prevent engine fouling. According to the agency’s draft chemistry, fate, release, and exposure assessment for the substance (PDF), workers may be exposed to ethylene dibromide when unloading or transferring it to and from storage containers, repackaging products containing ethylene dibromide, and cleaning and maintaining equipment that may have residual ethylene dibromide. Occupational non-users, who EPA describes as those who may be exposed to a substance while working near where it is being used, may be exposed to vapors while in close proximity to where ethylene dibromide is being handled. Some consumers—pilots of small noncommercial airplanes, for example—may also be exposed while refueling aircraft.

The draft risk evaluation includes a draft eight-hour, time-weighted average existing chemical occupational exposure value for inhalation exposures to ethylene dibromide of 0.00097 ppm, or 0.0075 mg/m3. The draft document explains that EPA may use this value “to support risk management efforts for ethylene dibromide under TSCA section 6(a).” For comparison, OSHA’s permissible exposure limit for ethylene dibromide is 20 ppm as an eight-hour TWA.

EPA is seeking input on the draft risk evaluation for ethylene dibromide until Oct. 19. During the comment period, the agency hopes to receive specific input on topics including any technologies or engineering controls related to exposure reduction since the 1980s, personal protective equipment used by workers, and leaded aviation fuel use patterns. The agency is also interested in exposure monitoring data from facilities relevant to the conditions of use it examined for ethylene dibromide.

The draft risk evaluation and supporting documents can be found on EPA’s risk evaluation webpage for ethylene dibromide. Further details and instructions for submitting comments are available in the Federal Register.