Decaf coffee is not safe for human consumption, health advocacy group warns

(CNN) – Some health advocacy groups are arguing that decaffeinated coffee is not safe for human consumption.

Those groups are petitioning the FDA to ban methylene chloride, a key chemical used to remove caffeine.

According to the Occupational Safety and Health Administration, that chemical is used for paint stripping, metal cleaning and degreasing, and other industrial processes.

Experts say methylene chloride has been designated as a carcinogen by the World Health Organization and Environmental Protection Agency, among others.

The state assembly in California recently introduced a bill to ban the chemical from the decaffeination process.

The FDA says it is currently reviewing the petitions.

An FDA spokesperson said in an email that residue limits of methylene chloride have been set to limit exposure.

Not all coffee brands use the same process for decaffeination.