Isolation and identification of some unknown substances in disposable nitrile-butadiene rubber gloves used for food handling.

In Japan, disposable gloves made from nitrile-butadiene rubber (NBR) are frequently used in contact with foods. In a previous paper, we investigated substances migrating from various gloves made of polyvinyl chloride, polyethylene, natural rubber and NBR. Zinc di-n-butyldithiocarbamate (ZDBC), diethyldithiocarbamate (ZDEC) used as vulcanization accelerators, di(2-ethylhexyl)phthalate (DEHP) used as a plasticizer and many unknown compounds that migrated from NBR gloves into n-heptane were detected by GC/MS. In this paper, six unknown compounds were obtained from one kind of NBR glove by n-hexane extraction and each was isolated by silica gel chromatography. From the results of NMR and mass spectral analysis of the six unknown compounds, their structures are proposed as 1,4-dione-2,5-bis(1,1-dimethylpropyl)cyclohexadiene (1), 2-(1,1-dimethylethyl)-4-(1,1,3,3-tetra methylbutyl)phenol (2), 2,6-bis(1,1-dimethylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (3), 2,4-bis(1,1,3,3-tetramethylbutyl)phenol (4), 2-(1,1-dimethylethyl)4,6-bis(1,1,3,3-tetramethylbutyl)phenol (5) and 2,4,6-tris(1,1,3,3-tetramethylbutyl)phenol (6). Compound 1 was observed in five of the seven kinds of NBR gloves, and compounds 2-4 and 6, which are not listed in Chemical Abstract (CA), were present in four kinds of gloves.

[Migrants from disposable gloves and residual acrylonitrile].

Disposable gloves made from polyvinyl chloride with and without di(2-ethylhexyl) phthalate (PVC-DEHP, PVC-NP), polyethylene (PE), natural rubber (NR) and nitrile-butadiene rubber (NBR) were investigated with respect to evaporation residue, migrated metals, migrants and residual acrylonitrile. The evaporation residue found in n-heptane was 870-1,300 ppm from PVC-DEHP and PVC-NP, which was due to the plasticizers. Most of the PE gloves had low evaporation residue levels and migrants, except for the glove designated as antibacterial, which released copper and zinc into 4% acetic acid. For the NR and NBR gloves, the evaporation residue found in 4% acetic acid was 29-180 ppm. They also released over 10 ppm of calcium and 6 ppm of zinc into 4% acetic acid, and 1.68-8.37 ppm of zinc di-ethyldithiocarbamate and zinc di-n-butyldithiocarbamate used as vulcanization accelerators into n-heptane. The acrylonitrile content was 0.40-0.94 ppm in NBR gloves.

[Necessity for total trichloride compound measurement in screening tests for workers exposed to trichloroethylene or 1,1,1,-trichloroethane].

In 9 series of physical examinations legally required for trichloroethylene (TCE) workers, levels of urinary total trichloride compounds (TTC) were revealed to be generally high in 323 specimens, including 250 male ones, collected from a medium sized company. Sixty four specimens (19.8%), including 56 male ones (22.4%), exceeded 300 mg/l which are regarded to correspond to the threshold limit for TCE in the air of the work site. Four specimens had over 900 mg/l. In all 323 specimens, however, no abnormalities were found with respect to specific gravity of blood, hemoglobin concentration and urinary tests. TTC concentration values increased in specimens in the last 4 physical checkups, compared with the values measured in the first 5. The cause of this increase seemed to be related to increases in the number of products and the hours of overtime work. Symptoms felt by these workers gradually subsided as they were continuously exposed to TCE for more than 2 or 3 years. Some workers of long service had a tendency toward addiction to TCE. In the legally required environmental monitoring of TCE, and other harmful organic solvents, the 8 workplaces fell into either classification 1 or 2, indicating that the environmental conditions are not harmful. More importantly, the above evaluations did not take into account long hours of overtime put in by those workers. Turning to the checkups of 1,1,1-trichloroethane workers, the results of legally required physical checkups and environmental monitoring were almost the same as those for TCE.(ABSTRACT TRUNCATED AT 250 WORDS)