Benzene Content In Gasoline Research Articles

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CONSUMER PRODUCTS Reactions ShareShare onFacebookTwitterWechatLinked InRedditEmail C&EN, 2022, 100 (43), p 5December 5, 2022Cite this:C&EN 100, 43, 5Letters to the editorMoose adventures in CanadaThe photo of the crash test dummy moose in Newscripts (C&EN, Sept. 19, 2022, page 32) brought back the memory of motoring with my wife on the Trans-Canada Highway north of Lake Superior in about 1980. As we registered in a motel in Wawa, Ontario, the desk clerk asked me if I had noticed a little red sports car in the lot. It and its driver had survived driving under a moose.Incidentally, when I had a summer job in the research lab of Canadian Industries Limited at McMasterville, Quebec, in 1947, the lab had a system of prizes: the One Bell Prize for a helpful bit of lab technique, the Two Bell Prize for finding a new substance of interest, the Three Bell Prize for a major advance, and the No Bell Prize for a conspicuous goof.Robert A. StairsPeterborough, OntarioRegulation of benzene in liquefied petroleum gasThe propane, butane, and isobutane mentioned in the article on benzene in dry shampoo (C&EN, Oct. 24/31, 2022, page 10) are sold as liquefied petroleum gas, known to the consumer as propane. Liquefied petroleum gas is a commodity produced by oil refineries and sold as a fuel for cooking, heating, grain drying, forklift trucks, and even backyard barbecues.The benzene discovery indicates contamination of some of it. As a commodity, it is easily commingled in distribution, as some may be supplied from multiple sources. Benzene in liquefied petroleum gas used as fuel may not be a concern, but caution is required when liquefied petroleum gas is used as a propellant in aerosol consumer products. In addition to cosmetic products, bug sprays and spray paints might be affected.The benzene content of gasoline is regulated. Is benzene regulated in liquefied petroleum gas?Paul E. EcklerWildwood, Missouri ACS 2021 IRS Form 990 availableThe American Chemical Society’s 2021 IRS Form 990 is now available on the ACS website. To access the information, go to www.acs.org/acsirsform990. Please scroll toward the bottom of the page to access the 2021 form and related Guide to Schedule J for explanatory information regarding ACS executive compensation. If you have any access problems, please contact [email protected]

Benzene Exposure and Cancer Risk from Commercial Gasoline Station Fueling Events Using a Novel Self-Sampling Protocol.

Tens of millions of individuals go to gasoline stations on a daily basis in the United States. One of the constituents of gasoline is benzene, a Group 1 carcinogen that has been strongly linked to both occupational and non-occupational leukemias. While benzene content in gasoline is federally regulated, there is approximately a thirty-year data gap in United States research on benzene exposures from pumping gasoline. Using a novel self-sampling protocol with whole air canisters, we conducted a gasoline pumping exposure assessment for benzene, toluene, ethylbenzene, and xylene (BTEX) on Baltimore, MD consumers. Geometric mean exposures (geometric standard deviations) were 3.2 (2.7) ppb,9.5 (3.5) ppb, 2.0 (2.8) ppb, and 7.3 (3.0) ppb, respectively, on 32 samples. Using the benzene exposures, we conducted consumer and occupational probabilistic risk assessments and contextualized the risk with ambient benzene exposure risk. We found that the consumer scenarios did not approach the 1:1,000,000 excess risk management threshold and that the occupational scenario did not exceed the 1:10,000 excess risk management threshold. Further, in all Monte Carlo trials, the ambient risk from benzene exposure exceeded that of pumping risk for consumers, but that in approximately 30% of occupational trials, the pumping risk exceeded the ambient risk.

Mycobiota of Oil-Contaminated Soil Samples and Their Abilities for Dibenzothiophene Desulfurization

ABSTRACTHigh sulfur content of crude oil leads to poor quality of oil products and many other negative consequences such as corrosion, catalyst poisoning and environmental pollution. Saudi Arabia is seeking to reduce sulfur content in diesel and gasoline to 10 ppm and to lower benzene content in gasoline to 1%. Biotechnological processes such as biodesulfurization can be considered an alternative or complement to conventional oil refining technologies. So, the objective of the present project is to isolate and identify endogenous fungal isolates capable of oil biodesulfurization. From 60 oil-contaminated soil samples collected from Saudi Arabia, 15 species belonged to 9 fungal genera were collected and identified morphologically and with ITS sequencing. Members of Aspergillus, Penicillium and Fusarium were the most prevalent in the investigated samples. Among the collected fungal species, only Stachybotrys bisbyiisolates were able to utilize dibenzothiophene (DBT) as the sole sulfur source. Stachybotrys bisbyi TUSb1 could desulfurize 99% of the DBT (0.3 mM) as the sulfur source by a co-metabolism reaction with other carbon sources through the same pathway as 4S (involves sequential oxidation of the sulfur part and cleaving of the C–S bonds), and produced 2-hydroxy biphenyl (2-HBP) during 7 days of incubation at 30°C and 180 rpm. Stachybotrys bisbyi TUSb1 showed broad specificity for removing sulfur in different sulfur-containing compounds.

SUCCESS OF FUEL QUALITY IMPROVING POLICY IN REDUCING BENZENE AIR CONCENTRATIONS IN BANGKOK

The Thai's policy in improving of fuel quality to the changing of emissions and concentrations of air pollutants in Bangkok is evaluated in this study. Benzene content in gasoline had been decreased from 3.5% (EURO II standard) to less than 1.0% (EURO IV standard) since the year 2012. The IVE (International Vehicle Emission) model was applied to develop emission factor of benzene taking into consideration actual fleets and characteristics of vehicles in Bangkok. These vehicles consisted of passenger car, motorcycle, van and pick up, taxi, bus and truck. Then, emission inventory of benzene emitted from mobile sources was calculated. It was found that about 83% of total emissions of benzene were contributed from motorcycle (43%) and passenger car (40%). Emission amounts were reduced from 1.32 x 10 3 ton/year to 0.57 x 10 3 ton/year as resulted from changing of fuel quality from EURO II to EURO IV standard. AERMOD dispersion model was used to simulate ambient ground level concentration of benzene prior and after implementing this policy. Results revealed significantly reduction of benzene concentrations in Bangkok's environment. Spatial distribution of benzene pollution map illustrated that areas having annual concentration higher than 1.7 g/m 3 (the Thai's air quality standard for benzene) were still only found in traffic-congested zone of the central business district in the metropolitan area.

Properties of Ethanol Fuel Blends Made with Natural Gasoline

This project looks at the potential of blending ethanol with natural gasoline to produce Flex-Fuels (ASTM D5798-13a) and high-octane, mid-level ethanol blends. Eight natural gasoline samples were collected from pipeline companies or ethanol producers around the United States. Analysis of the natural gasoline shows that the samples are 80–95% paraffinic, 5–15% naphthenic, 3% or less aromatics, and the balance olefins. The paraffins were typically pentane and isopentanes. The benzene content ranged from approximately 0.1 to 1.2 wt % such that blends of E30 or more would meet United States Environmental Protection Agency (U.S. EPA) limits for the benzene content in gasoline. The sulfur content in the natural gasoline ranged between 4 and 146 ppm. Assuming the lowest ethanol content in Flex-Fuel of 51 volume percent (vol %), a natural gasoline blendstock would be required to have 20 ppm sulfur or less for the finished fuel to meet the upcoming U.S. EPA Tier 3 gasoline sulfur limit. The research octane number ...

Soft Sensor Development for the Estimation of Benzene Content in Catalytic Reformate

As vehicle emission standards become more stringent, there is an increasing need for continual monitoring of benzene content in gasoline. Since on-line analyzers are often unavailable, and laboratory analyses are infrequently obtained, soft sensors for the estimation of benzene content of light reformate are developed. Soft sensors are developed using linear and nonlinear identification methods. Experimental data are acquired from the refinery distributed control system (DCS) and include continuously measured variables and analyzer assays available on-line. In the present work, the development of a finite impulse response (FIR) model, an output error (OE) model, and a Hammerstein–Wiener (HW) model is presented. To overcome the problem of selecting the best model parameters by trial and error, genetic algorithms and pattern (direct) search were used. On the basis of developed soft sensors, it is possible to entirely replace on-line analyzers with soft sensors by embedding the model in a DCS on-site.

서울시 도로변, 터널 및 주거지역 대기 중 유해 휘발성 유기화합물의 특성

Hazardous volatile organic compounds (HVOCs) have been increasingly getting concern in urban air chemistry due to photochemical smog as well as its toxicity or potential hazards. In this study, we investigated their concentrations and the properties in tunnel, urban roadside and residential area. As a result, among 36HVOCs measured in this study, BTEX (benzene, toluene, ethylbenzene, xylene) and dichlorodifluoromethane, 1,2,4-trimethylbenzene, trichlorofluoromethane were detected above the concentration of <TEX>$1{\mu}g/m^3$</TEX> in every sampling site and the most abundant compound was toluene. The other compounds were detected at trace level or below the detection limit. In addition, we found that three CFCs (chlorofluorocarbons), such as CFC-12, CFC-11, CFC-113, were persistently detected because of the emission in the past. Toluene to benzene ratio (T/B) at tunnel and roadside were calculated to be 4.3~5.3 and at residential area 15.4, suggesting that the residential area had several emission sources other than car exhaust. The ratio of X/E (m,p-xylene to ethylbenzene) ratio was calculated to be 1.8~2.1 at tunnel, 1.7 at roadside and 1.2 at residential area, which means this ratio reflected well the relative photochemical reactivity between these compounds. Good correlation between m,p-xylene and ethylbenzene (<TEX>$r^2$</TEX> > 0.85) were shown in every study sites. This indicated that correlation between <TEX>$C_2$</TEX>-alkylbenzenes were not severely affected by 3-way catalytic converter. In this study, it was demonstrated that the concentration of benzene was very low, compared with national air quality standard (annual average of <TEX>$5{\mu}g/m^3$</TEX>). Its concentration were <TEX>$2.52{\mu}g/m^3$</TEX> in roadside and <TEX>$1.34{\mu}g/m^3$</TEX> in residential area. We thought this was the result of persistent policy implementation including the reduction of benzene content in gasoline enforced on January 1, 2009.

Studies on commuters' exposure to BTEX in passenger cars in Kolkata, India

Commuters' exposure to volatile organic compounds (VOCs) especially BTEX travelling in passenger cars in Kolkata, India were quantified in Phase I (2001-2002) and Phase II (2003-2004). Monitoring was made inside and in the immediate outside of passenger cars fitted with and without catalytic converters using different types of fuels, along two congested urban routes. During Phase I of the study, the benzene content in gasoline was 5% and the mean concentration of in-vehicle benzene in cars without catalytic converter was found to be as high as 721.2 microg/m3. In Phase II when the benzene content was reduced to <3% and with modified engine type, the mean in-vehicle benzene concentration was reduced to 112.4 microg/m3. The in-vehicle concentration varied with engine type and age of the vehicle. Roadside ambient mean concentration of benzene was 214.8 microg/m3 and 30.8 microg/m3 in Phase I and Phase II respectively.

Assessment of Air Quality After the Implementation of Compressed Natural Gas (CNG) as Fuel in Public Transport in Delhi, India

Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM(10), CO, SO(2) and NO(x)) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO(2) and CO concentrations, while the NO(x) level was increased in comparison to those before the implementation of CNG. Further, SPM, PM(10), and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.

Simple analysis of volatile organic compounds (VOCs) in the atmosphere using passive samplers.

A simple analysis of volatile organic compounds (VOCs), such as benzene, toluene, m,p-xylene, and o-xylene, at low levels in the atmosphere was conducted using passive samplers. The methods were applied to analyzing the behavior and origin of VOCs in Kyoto City. The passive samplers were exposed for 7 - 14 days at sampling sites in Kyoto City and for 30 days in the mountains (Mt. Hiei and Mt. Daimonji). Shibata gas-tube samplers packed with activated carbon were used for the determination of VOCs. The absorbed VOCs were extracted into carbon disulfide (CS2) and measured by FID-GC. The determination limits and relative standard deviations for VOCs were 0.3 microg/m3 and 3%, respectively. The samplers were set up at 5 sites in March, 2001 and at 13 stations on Mt. Hiei in November, 2002. The average concentrations of ambient benzene, which were higher than the environmental criterion (3.0 microg/m3), except for those on Mt. Daimonji from March, 2001, to February, 2002, decreased to below 3.0 microg/m3 from March, 2002, to February, 2003. The decrease in ambient benzene may have been due to a decrease in the benzene content in gasoline by the end of 1999, and also by implementation of the Pollutant Release and Transfer Register (PRTR) Act in 2001.

Verification of the effect on risk due to reduction of benzene discharge

The time course of ambient benzene level and benzene discharge was investigated. Data obtained by continuous monitoring and monthly monitoring showed a decreasing trend of ambient benzene level. The rate of decrease was around 22–25% per two years from FY 1997 to FY 1999. The discharge data of benzene reported by several organizations were collected and re-arranged to estimate the total discharge in Japan. The total amount of benzene discharged decreased by 25% from 1997 to 1999. Risk reduction due to the regulation of benzene content in gasoline as predicted in our previous report was verified by the obtained data.

Population risk assessment of ambient benzene and evaluation of benzene regulation in gasoline in Japan

The aggregate population cancer risk due to ambient benzene was evaluated for the entire Japanese population. This was done using data of ambient NOx levels measured at as many as 2000 air pollution monitoring stations nationwide and the regression equation between the levels of benzene and NOx obtained by continuous monitoring. The population-weighted exposure levels for the roadside population and general-environment population were calculated to be 2.1 ppb and 1.0 ppb, respectively. Eighty-four percent of the entire population was exposed to a lifetime cancer risk level of 1 × 10−5 or greater, and the annual number of cancer deaths was estimated to be 29.6 cases at the 1997 benzene level. Due to the regulation which established the upper limit of benzene content in gasoline to be 1 vol. % by January 2000, the total emission of benzene was estimated to be reduced by 27%, compared to 1993. The annual number of cancer deaths was expected to be reduced by 8.8 cases through the regulation of benzene in gasoline. Japanese petroleum companies have estimated the annual cost of the reduction of the benzene content in gasoline to be 25.6 billion yen. The cost per life saved by the regulation of benzene in gasoline is estimated to be 2.9 billion yen. The method implemented in this study to predict population risk is useful for identifying potential risk management options and evaluating their effectiveness before making decisions.

Review of new evidence regarding the relationship of gasoline exposure to kidney cancer and leukemia.

Four new or updated epidemiologic studies were presented at a meeting on the health effects of gasoline exposure held in Miami, Florida, November 5-8, 1991. A focus of these studies was whether there is a relationship between gasoline exposure and kidney cancer and leukemia. For gasoline distribution workers, who have a relatively high exposure, there was some evidence for a kidney cancer relationship in three studies but none in the fourth. There was evidence for an acute myelocytic leukemia relationship in three studies. The fourth study dealt only with kidney cancer. It is possible that the benzene content of gasoline was responsible for the leukemia findings. It is uncertain whether gasoline exposure is a cause of kidney cancer.