Health assessment of gasoline and fuel oxygenate vapors: Generation and characterization of test materials

Abstract

In compliance with the Clean Air Act regulations for fuel and fuel additive registration, the petroleum industry, additive manufacturers, and oxygenate manufacturers have conducted comparative toxicology testing on evaporative emissions of gasoline alone and gasoline containing fuel oxygenates. To mimic real world exposures, a generation method was developed that produced test material similar in composition to the re-fueling vapor from an automotive fuel tank at near maximum in-use temperatures. Gasoline vapor was generated by a single-step distillation from a 1000-gallon glass-lined kettle wherein approximately 15-23% of the starting material was slowly vaporized, separated, condensed and recovered as test article. This fraction was termed vapor condensate (VC) and was prepared for each of the seven test materials, namely: baseline gasoline alone (BGVC), or gasoline plus an ether (G/MTBE, G/ETBE, G/TAME, or G/DIPE), or gasoline plus an alcohol (G/EtOH or G/TBA). The VC test articles were used for the inhalation toxicology studies described in the accompanying series of papers in this journal. These studies included evaluations of subchronic toxicity, neurotoxicity, immunotoxicity, genotoxicity, reproductive and developmental toxicity. Results of these studies will be used for comparative risk assessments of gasoline and gasoline/oxygenate blends by the US Environmental Protection Agency.

Health assessment of gasoline and fuel oxygenate vapors: Neurotoxicity evaluation

“…Motor activity and performance in the functional observational battery (FOB) was evaluated in all 20 animals. The animals were satellite groups of a larger subchronic toxicity study, and the generation and composition of the vapor concentrations as well as additional details on the exposure methodology are reported in companion articles ( Henley et al, 2014 ; Clark et al, 2014 ).…”

“…In 1994, the U.S. Environmental Protection Agency (EPA) issued a final rule under the Act which added new health effects information and testing requirements to the Agency’s existing registration requirements. As described in more detail in a companion paper ( Henley et al, 2014 ), requirements include inhalation exposures to evaporative emissions of the gasoline or additive in question. The health endpoints include assessments for standard subchronic toxicity, neurotoxicity, genotoxicity, immunotoxicity, developmental and reproductive toxicity, and chronic toxicity/carcinogenicity.…”

Diesel Oil Vapor Inhalation: Risk Factor for Heart Attack

“…In 1994, the U.S. Environmental Protection Agency (EPA) issued a final rule under the Act which added new health effects information and testing requirements to the Agency's existing registration requirements. As described in more detail in a companion paper (Henley et al, 2014) include inhalation exposures to evaporative emissions of the gasoline or additive in question. The health endpoints include assessments for standard subchronic toxicity, neurotoxicity, genotoxicity, immunotoxicity, developmental and reproductive toxicity, and chronic toxicity/ carcinogenicity.…”

“…Key differences between whole gasoline and the vaporized gasoline are the significantly greater concentration of C4 and C5 constituents and depletion of C7-C12 aromatic constituents in the vapor condensate. The equilibrium vapor and vapor condensate are also less complex and have a lower average molecular weight and specific gravity [4]. Human studies of both short-and long-term exposures to combustion emissions and ambient fine particulate air pollution have been associated with measures of genetic damage.…”

Introduction: Gasoline health effects and risk management

“…The second paper in this issue ''Health Assessment of Gasoline and Fuel Oxygenate Vapors: Generation and Characterization of Test Materials'' (Henley et al, 2014) describes the extensive research involved in designing a method to generate the evaporative emissions used in these toxicology studies. Due to the extreme flammability of gasoline, it was not a trivial effort to develop and maintain safe handling procedures at several contract laboratories to ship, store and perform studies with the test articles.…”