Aqueous extraction of N-nitrosamines from elastomers

Elastomers compounded with accelerators or stabilizers derived from dialkylamines have been found to contain the corresponding N-nitrosodialkylamines. Previous work showed that the N-nitrosamines are evolved from heated elastomers; we have not found they are also extractable in water. In the absence of the dialkylamino compound in the elastomer, no N-nitrosodialkylamines were detected. Generally, less than 250 parts of N-nitrosamine per billion parts of elastomer was detected after extracting for one or five days at room temperature or 100 degrees C. Compounded and cured polychloroprene, ethylene-propylene-diene terpolymer, chlorosulfonated polyethylene, and natural rubber, as well as several commercial rubber articles, were included in this study. Controls were run to determine the background levels of N-nitrosamines and the recovery of N-nitrosamines from the extraction solvent. N-nitrosamines were quantitated using gas chromatography with thermal energy analyzer detection.