N-nitrosodimethylamine content of US and Canadian beers

A total of 194 beers (148 US and 46 Canadian) were analysed for volatile N-nitrosamines. The sampling was designed to include different types of beers brewed from malts at all commercial-scale malt houses by the major beer manufacturers in both countries. N-Nitrosodimethylamine (NDMA), the only volatile N-nitrosamine detected, was found in 56% of the beers (detection level, 0.05 microgram/kg), at a mean level of 0.074 microgram/kg. The results indicate that NMDA levels in present-day US and Canadian beers are approximately 1-5% of what they were a decade ago.