Identification of migrants from nitrile-butadiene rubber gloves

Abstract

Polyvinyl chloride gloves containing di(2-ethylhexyl) phthalate are restricted for food contact use. In their place, disposable gloves made from nitrile-butadiene rubber (NBR) are used in contact with foodstuffs. Some unknown substances were found to migrate into n-heptane from NBR gloves. By GC/MS, HR-MS and NMR, their chemical structures were confirmed to be 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (used as a plasticizer), 4,4′-butylidenedi(6-tert-butyl-m-cresol), a mixture of styrenated phenols consisting of 2-(α-methylbenzyl)phenol, 4-(α-methylbenzyl)phenol, 2,6-di(α-methylbenzyl)phenol, 2,4-di(α-methylbenzyl)phenol and 2,4,6-tri(α-methylbenzyl) phenol (used as antioxidants), and 2,4-di-tert-butylphenol, which seems to a degradation product of antioxidant. Migration levels of these compounds were 1.68 μg/cm2 of 2,4-di-tert-butylphenol, 2.80 μg/cm2 of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 46.08 μg/cm2 of styrenated phenols and 4.22 μg/cm2 of 4,4′-butylidenedi(6-tert-butyl-m-cresol) into n-heptane, respectively. The content of total styrenated phenols was 6,900 μg/g in NBR gloves.