Visual and ocular changes associated with exposure to two tertiary amines.

AIMS: To determine if exposure to dimethylisopropanolamine (DMIPA) and dimethylaminoethanol (DMAE) in a label printing plant was associated with visual disturbances and/or ocular changes. METHODS: Questionnaires, eye examinations (visual acuity, contrast sensitivity at 2.5% and 1.25% contrast, slit lamp biomicroscopy, and pachymetry), and industrial hygiene monitoring for DMIPA and DMAE were performed over a two week period. RESULTS: Eighty nine per cent of line workers reported having experienced blurry vision while at work in the past 12 months, compared to 12.5% of prime workers. A total of 108 full shift personal breathing zone (PBZ) air samples for the amines were collected. The mean time weighted average (TWA) concentration of DMIPA was significantly higher in the line division than in the prime division, as was the mean TWA concentration for total amines. The mean TWA concentration of DMAE was higher in the prime division than the line division. Higher levels of total amines were associated with increased risk of reporting blurry vision, halo vision, and blue-grey vision. The risk of corneal opacity rose with increasing exposure to total amines. The prevalence of corneal opacity also increased with increasing concentration of total amines. Median corneal thickness increased with increasing grades of corneal opacity. There was a statistically significant relation between total amine concentration and increased risk of reduced bilateral visual acuity and 2.5% contrast sensitivity. CONCLUSIONS: Exposure to tertiary amines was associated with blurry, halo, and blue-grey vision, corneal opacity, and decrements in visual acuity and contrast sensitivity at 2.5% contrast.

Application of multidimensional gas chromatography-mass spectrometry to the determination of glycol ethers in air.

The applicability of multidimensional gas chromatography-mass spectrometry to the analysis of five glycol ethers in air was demonstrated. Air samples were collected on charcoal tubes and desorbed with 5% methanol in methylene chloride as is described in method 1403 of the National Institute for Occupational Safety and Health Manual of Analytical Methods. The glycol ethers were determined by multidimensional gas chromatography-mass spectrometry. The limit of detection was 5 to 7 micrograms/sample for each compound.

Occupational vitiligo due to unsuspected presence of phenolic antioxidant byproducts in commercial bulk rubber.

We investigated the occurrence of cutaneous depigmentation (vitiligo) among employees of a company that manufactured hydraulic pumps. The interiors of these pumps were injection-molded with rubber. We identified a small but significant cluster of vitiligo cases among a group of employees who frequently handled the rubber used in this injection molding process. Although none of the additives specified in the rubber formulations was a phenolic or catecholic derivative, known to be potential causes of chemically induced vitiligo, gas chromatographic analysis identified a para-substituted phenol (2,4-di-tert-butylphenol, DTBP) in solid samples of the most frequently used rubber. Surface wipe analysis confirmed that workers could be exposed to DTBP from simple handling of the rubber. We subsequently established that the solid bulk rubber used as the base in these stock rubber formulations contained both DTBP and smaller quantities of p-tert-butylphenol. Both had formed as unsuspected byproducts during chemical synthesis of two antioxidants added to the solid bulk rubber by a major rubber supplier. We conclude that the unsuspected presence of potential chemical depigmenting agents in solid bulk rubber, from which industrial rubber products are formulated, may contribute to the occurrence of occupational vitiligo, and that a simple review of ingredients in rubber formulations is inadequate to detect their presence.

Fourier transform infra-red spectroscopy applied to hazardous waste: I--Preliminary test of material analysis for improvement of personal protection strategies.

Many chemicals, when mixed, can produce potentially hazardous effects which are harmful to human health and to the environment such as heat, pressure, fire, explosion, violent reaction, and toxic dusts, mists, fumes, and/or gases. Waste chemicals handled on a remedial action site are analyzed by simple chemical methods for compatibility. Because it is difficult to base worker and community protection programs on this limited knowledge of material content, extreme precautions must be taken to ensure safety to all working on or living near hazardous waste remedial action sites. The approach used in this study involved the application of Fourier transform infra-red spectroscopy (FTIR) to the analysis of samples taken from the Chem-Dyne remedial action hazardous waste site. The data generated are compared to the results obtained using compatibility and GC-MS analysis procedures. Illustrations are given of improved personal protection strategies, based on drum material composition obtainable by FTIR. The requirements for further testing are defined.

Establishing a protocol from laboratory studies to be used in field sampling operations.

A laboratory procedure is described that has been used in determining the breakdown products of plastic compounds used in injection molding operations. These compounds include polyvinyl chloride, polystyrene, acrylonitrile-butadiene-styrene, methyl methacrylate, polyethylene, polypropylene, and nylon. Laboratory samples were generated at injection molding temperatures and collected on various solid sorbents. Detector tubes were used for qualitative information to indicate whether certain classes of compounds were present. Compounds identified from the analyses of these laboratory samples are listed. Qualitative gas chromatography-mass spectormetry (GC/MS) data obtained from charcoal tube samples collected at a tire molding and a rubber producing company are also presented.