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Comments on: ENVIRONMENTAL TOBACCO SMOKE: A GUIDE TO WORKPLACE SMOKING POLICIES [Dratltj EPA 400/6-90/004 Response Addressing: Chapter 2: Measuring ETS in the Air and Body Section: Other Surrogates Topic: Benzene Prepared by: David L. Heavner, M.S. Senior R&D Chemist R.J. Reynolds Tobacco Company October 1990

SUMMARY: The statements concerning benzene in the EPA draft document, "Environmental Tobacco Smoke: A Guide to Workplace Smoking Policies", are misleading by errors of omission. The document fails to point out many other sources of benzene in the environment (naturally and as a contaminant): soil, water, food, outdoor ambient air, and most significantly, emissions from the operation of motor vehicles. Indoor air benzene levels from all sources, including environmental tobacco smoke are insignificant - approximately 1000 times less than the current regulatory workplace exposure standards. COMMENTARY: Commentary is provided in six sections following: 1) Introduction, 2) Background Information, 3) Industrial/Commercial Uses, 4) Inhalation and Metabolism of Benzene, 5) Total Exposure/Daily Intake, and 6) Conclusion. 1.0 Introduction Benzene is a ubiquitous organic compound that is produced from natural products such as coal tar and crude oil. In the early 1900s, benzene became widely available and was used in the chemical industry as a starting material for synthetic processes. Today, most of the benzene produced is used in large-scale chemical operations; therefore, the magnitude of potential exposure is greatest for occupational workers. In addition to those exposed occupationally, a large segment of the U.S. population OD is exposed daily to benzene as fugitive emissions from petroleum facilities (re5neries,M Q1 transportation and storage centers, service stations) and as a combustion productN ~ cd

from tobacco smoke and wood fires, and most significantly from auto exhaust. In 1989, in the Fifth Annual Report on Carcinogens, the U.S. Department of Health and Human Services estimated that in 1976, 1 billion pounds of benzene were r.aeased into the atmosphere from the refueling and operation of approximately 130 million motor vehicles [1]. This translates into 7.8 pounds of benzene/vehicle/year. In contrast, a 1 pack/day smoker would generate approximately 0.008 pounds of benzene/smoker/year, assuming that 0.5 mg of benzene are generated from one cigarette (mainstream + sidestream) [2]. In other words, a smoker would generate only 1/10th of one per cent (0.10%) the amount of benzene generated by one automobile in a given year. Benzene has also been found in soil, fresh water and salt water, drinking water, groundwater, rural and urban outdoor ambient air environments, as a contaminant in solvents, and naturally-occurring in foods. In short, exposure to benzene is prevalent in our society as a function of everyday activities. The purpose of this document is to place into perspective the exposure of the general population to benzene from all sources and to compare the magnitude of normal background exposure to benzene exposure from environmental tobacco smoke (ETS). 2.0 Background Information ~ ~ 4b Cn Nt 0

2.1 Physical data Benzene (CA), a clear and colorless liquid, has physical and chemical properties as follows: molecular weight: 78.1 boiling point: 80.1°C melting point: 5.5°C vapor pressure: 74.6 mm @ 20°C density: d4' 0.8787 g cm' refractive index: nD' 1.5016 solubility: slightly soluble in H2O; miscible with most organic solvents, glacial acetic acid and oils 2.2 Guidelines and Standards for Exposure 2.2.1 Historical Several governmental agencies and professional societies have established guidelines and standards for benzene exposure. These guidelines are based on the best possible information available from animal studies, human studies and industrial experience. Recommended benzene control levels have been ~ M U1 ~ 3 ~

gradually reduced in the U.S. since 1920 when Massachusetts and several other states had an 8-hr. 100 ppm limit. By 1940, the maximum level had been reduced to 35 ppm; however, the limit was raised to 100 ppm as a Federal War Time Standard. In 1946, the American Conference of Governmental Industrial Hygienists (ACGIH) adopted the 100 ppm standard. By 1957, the 8-hr. ACGIH time-weighted-average (TWA) standard had been reduced to 25 ppm. In 1969, the American National Standards Institute (ANSI) set the TWA at 10 ppm with a 25 ppm ceiling limit. In 1972 and 1974, the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH), respectively, adopted the ANSI standard. In addition, NIOSH established a 5-ppm action level at that time. Since then, NIOSH has lowered its standard to 1 ppm [3]. The reduction of benzene exposure limits has been motivated predominantly by two factors: an increase in the number of health effect studies implicating benzene with adverse effects and an improvement in analytical instrumentation over the last four decades that has improved the limits of detection and quantitation. 2.2.2 Currently accepted TLV's, PEL's, BErs ACGIH TLV: 10 ppm (32 mg/m')/8 Hour TWA OSHA PEL 10 ppm (32 mg/m')/8 Hour TWA 4

1 ppm (3.2 mg/m')/8 Hour TWA NIOSH REL: 1 ppm (3.2 mg/m')/60 Minute Ceiling Limit ACGIH BEI: phenol in urine-50 mg/1 benzene in mixed-exhaled air- 0.08 ppm benzene in end-exhaled air-0.12 ppm Threshold Limit Values (TLV's) refer to the ACGIH 8-hour average workplace concentration below which day-to-day repeated exposures show no adverse effect. Permissible Exposure Limits (PELs) refer to the OSHA 8-hour average workplace concentration below which day- to-day exposures show no adverse effect. Recommended Exposure Limits (RELs) refer to the NIOSH 60-minute ceiling value below which exposures show no adverse effect. Biological Exposure Indices (BEIs) serve as a reference to overall exposure through the measurement of biological specimen endpoint determinants. 2.2.3 Supreme Court Ruling on Benzene In 1978, OSHA established the benzene PEL standard at 1 ppm (3.2 _mg/m'); this level was an order of magnitude less than the ACGIH TLV of 10 ppm. However, on July 2,1980, the United States Supreme Court struck down the 1 ppm OSHA exposure standard for benzene. 5

The court ruled that a finding of significant risk had not been established prior to establishing the standard [4]. In the years that followed, OSHA began a project to re-evaluate PELs for all of its target substances. For this project, OSHA relied heavily on ACGIH and NIOSH documentation and guidance as well as other health effects literature data to determine whether significant risks occur at a given level. The project culminated in the promulgation of a new standards list with the benzene PEL set at 10 ppm for certain industries exempt from the 1 ppm TWA or for industries where the 1 ppm standard was stayed or otherwise not in effect (53 FR 20960, June 7, 1988). 3.0 ' Industrial/Commercial Uses 3.1 Use in manufacturing processes The use of benzene in manufacturing has been reduced over the last twenty years due to the removal of benzene from solvents used in daily operations. In the past, Turkish and Italian shoe factories (and presumably others) used inks, dyes, and glues containing benzene, either intentionally or as a contaminant [5,6]. In the 1940s, Swedish rubber raincoat factories used benzene in their processes [3]; a rubber coating plant in Massachusetts reportedly used benzene in its operations as late as 1979 [7]. The use of 6

benzene in tire manufacturing processes is well-documented [6]. Finally, rotogravure facilities have used benzene as a solvent for inks and as a solvent to clean printing presses [8]. Benzene use in industry as a solvent or thinner has decreased in the last 20 years due to stricter government regulations. 3.1.1 Workplace air concentrations A study to measure benzene occupational exposure in 40 large and small workplaces in Turkey was conducted in 1987. The concentration of benzene in the air ranged from 0 to 110 ppm in facilities used to manufacture shoes, tires, leather goods, and farm equipment. It was noted that there had been a decline in the use of benzene since an earlier study in 1972 although the benzene concentration in solvents still ranged from 3 to 7.5% [9]. A 1976 study reported that benzene concentrations ranged from 200 to 500 ppm in an Italian shoe factory where inks and glues containing benzene were used [10]. In the Swedish rubber raincoat industry study, 184 workers were exposed to benzene concentrations as high as 5236 ppm [3]. Exposures at this high level are extremely rare (even 40 years ago). 7

Benzene concentrations of 5 to 50 ppm with a peak of 140 ppm were found in a Massachusetts rubber coating plant in 1979 [7). Benzene concentrations near rotogravure machines in printing facilities have been found to range from 200 to 400 ppm with a peak of up to 1500 ppm [8). 3.2 Use in the chemical industry Currently, benzene is used in the chemical industry as a starting material, or as an intermediate, for the production of important commercial and agricultural products: dyes, pesticides, plastics, elastomers, and resins. In addition, benzene has in the past been used as an important component of industrial and commercial solvents. Its intentional use in solvents has gradually decreased; however, benzene is still found as an impurity in some glues, rubber cements, and commercial solvents. Generally, in the chemical industry, benzene is recaptured in "closed-loop" processes although some benzene does escape as fugitive emissions. 3.2.1 Workplace air concentrations A mortality cohort study was conducted at the Dow Chemical 8

Company in 1978 for workers exposed to benzene from 1940 to 1973. These workers were exposed to concentrations of 2 to 25 ppm [11]. Another chemical worker cohort study was conducted in 1987. This study included 4,602 workers exposed for at least 6 months between 1946 and 1947. These workers were reported to have a cumulative exposure of 180 to 719 ppm/month [12]. . 3.3 Petroleum refinery/handling operations The major use of benzene in the past was as a blend component in gasoline. This use has been reduced in the U.S., but continues in other countries. The benzene content of crude oil varies from near zero to approximately 1%. Estimates of the benzene concentration in gasoline range from 1 to 15%; in the U.S., the benzene concentration averages 1 to 2% by volume [3]. Fugitive emissions exposure to benzene may occur in workers at any stage of the operation: drilling, loading and transport to the refinery, off-loading at the refinery, refining, shipping to the storage facility and to the marketing station. Finally, the end-user is exposed to fugitive emissions of benzene while filling the tank at a service station (unless a vapor recovery system is installed). 9