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At least 19 recordsLinked to original sources
PubMed2007

Task- and time-dependent weighting factors in a retrospective exposure assessment of chemical laboratory workers.

A chemical exposure assessment was conducted for a cohort mortality study of 6157 chemical laboratory workers employed between 1943 and 1998 at four Department of Energy sites in Oak Ridge, Tennessee, and Aiken, South Carolina. Previous studies of chemical laboratory workers have included members within professional societies where exposure assessment was either limited or not feasible, or chemical processing employees where laboratory and production workers were combined. Because sufficient industrial hygiene records were unavailable for all four sites, weighted duration of employment was used as a surrogate for the magnitude of exposure. Potential exposure indices were calculated for each worker using number of days employed and weighting factors for frequency of contact and year of employment. A total of 591 unique laboratory job titles indicative of a chemical laboratory worker were collapsed into 18 general job title categories. Through discussions with current and retired workers, along with examination of historical organizational charts and job descriptions, the percentage of time with activities involving the direct handling of chemicals in the laboratory was estimated for each job title category. Scaled weighting factors of 1, 0.6, 0.3, and 0.05 were assigned to the job title categories representing 100%, 60%, 30%, and 5% of daily activities handling chemicals, respectively. Based on limited industrial hygiene monitoring data, personal radiation monitoring records, and professional judgment, weighting factors that declined 4% annually were applied to each year to account for improvements in laboratory technique, advancements in instrumentation, improvement in engineering controls, and increased safety awareness through time. The study cohort was separated into three categories of chemical exposures based on department level information: (1) inorganic, (2) mixed inorganic and organic, and (3) unknown. Potential exposure indices ranged from 0.15 to 6824.5 with a median value of 377.5 and a mean equal to 884.2. This exposure assessment method is useful for epidemiologic analyses when quantitative exposure data are absent or insufficient.

Air Pollutants, Occupational↗
PubMedDate not supplied

Report of the Howard Hughes Medical Institute's workshop on the performance of laboratory chemical hoods.

The Howard Hughes Medical Institute sponsored a workshop on laboratory chemical hoods on June 8, 9, and 10, 1998, that brought together 24 experts in the field of laboratory chemical hoods to critically assess the information known about hood performance. Workshop participants developed 31 consensus statements that reflect their collective views on the body of knowledge or lack thereof, for laboratory chemical hoods. The consensus statements fall into four broad categories: (1) hood selection, use, and operation; (2) hood and laboratory design issues; (3) ventilation system design issues; and (4) hood performance testing. The consensus statements include 26 statements on what is known and unknown about the performance of laboratory chemical hoods, 2 statements of definition, and 3 statements that reflect the participants' agreement not to agree. The brief commentary that follows each consensus statement provides guidance and recommendations.

Certification↗
PubMed1998

An assessment of the exposure of technicians working in a chemical laboratory for aromatic hydrocarbons at Neftochim, Burgas.

The average exposure to aromatic hydrocarbons per working shift of laboratory assistants at a chemical laboratory were measured. The laboratory is one of the service departments for four different production departments at Neftochim, Burgas--the largest oil refinery in Bulgaria. Long-term sampling of the air from different workplaces in the laboratory was performed by sampling charcoal sorbent tubes (type CT-CN-2), manufactured by Higitest (type NIOSH). The concentration of benzene, toluene, ethyl benzene, xylene and isopropyl benzene in the air at the laboratory was determined by gas chromatography using the Varian MEGA 1 with a flame ionisation detector and Inowax capillary column. The measured exposure levels of toxic substances in the aromatic hydrocarbons analysis laboratory were as follows: Benzene, 0.15-1.3 mg/m3, in single samples its concentration was 4.06-8.63 mg/m3; toluene, 0.15-0.46 mg/m3, in single samples its concentration was 5.5-15.62 mg/m3; ethyl benzene in most samples was 0.02 mg/ m3, in single samples its concentration was 20.68 mg/m3; xylene in most samples was 0.4 mg/m3, in single samples its concentration was 0.51-1.68 mg/m3; isopropyl benzene in most samples was 0.1 mg/m3, in single samples its concentration was 0.20-1.12 mg/m3. The results, obtained by measuring the average work-shift exposure of laboratory assistants to aromatic hydrocarbons in the air at the analytical laboratories, show that the measured concentrations are smaller than the respective threshold limit values. Bearing in mind, however, that some of these substances have an effect on the human organism, exposure to them is excessively hazardous for laboratory technicians.

Bulgaria↗