The U.S. Food and Drug Administration (FDA) has issued a Threshold of Regulation (TOR) exemption (TOR-2021-003) for the use of metal carbides and metal carbide alloys as components of ceramic coatings in repeat-use applications. These applications include food processing equipment parts – such as nozzles, bearings, seal rings, pumps, etc. – and cutting tools, saws, and other applications where these substances provide a durable, abrasion- and corrosion-resistant coating.

By way of background, a TOR exemption is based on evidence that the dietary exposure level from the intended use of the food contact substance (FCS) is below 0.5 parts per billion (ppb) and the FCS is not a known carcinogen. TOR exemptions may be used by any manufacturer or supplier for the specified uses of the FCS under the intended conditions of use (without the need for an FCN).

The FDA stated that this action was taken because the Agency has reviewed the use of metal carbides in food processing equipment through numerous food contact notifications (FCNs) and has received other inquiries on its use. Based on these reviews, FDA concluded that “metal carbides remain stable and intact, chemically inert, and resistant to corrosion and abrasion under their intended conditions of use” and that “[t]here is little or no likelihood that components of metal carbides would migrate to food at other than insignificant amounts, nor would the metal carbides otherwise affect food…”  Additionally, the Agency noted that it “is not aware of any study showing these food contact substances to be carcinogenic in humans or in animals.” (See FDA Issues Threshold of Regulation Exemption for Metal Carbides in Food Processing Equipment.)