U.S. – The U.S. Food and Drug Administration (FDA) has issued a Threshold of Regulation (TOR) exemption for the use of metal carbides and metal carbide alloys as a component or ceramic coating in repeat-use applications such as parts in food processing equipment.

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 itself is not a known carcinogen.

An FCS is any substance that is intended for use as a component of materials used in manufacturing, packing, packaging, transporting, or holding food, if such use of the substance is not intended to have any technical effect in such food.

Carbides are compounds composed of carbon generally prepared from metals or metal oxides at high temperatures (1500 °C or higher) by combining the metal with carbon and can be used in key industrial applications.

TOR exemptions may be applied by any manufacturer or supplier for the laid out uses of the FCS under the intended conditions of use.

 Federal law requires companies who wish to use a food contact substance to obtain pre-market authorization from the FDA. 

Authorization for food contact substances is typically obtained through the submission of a Food Contact Substance Notification (FCN) to FDA.

 An FCN authorization applies only to the FCS prepared by the manufacturer identified in the FCN.

The FDA took this action after reviewing the use of metal carbides in food processing equipment through numerous FCNs and receiving other inquiries on its use.

Based on the reviews, the agency has concluded that metal carbides remain stable and intact, chemically inert, and resistant to corrosion and abrasion under their intended conditions of use.

There is little to no likelihood that components of metal carbides will migrate to food in significant amounts, nor will the metal carbides otherwise affect food hence the agency has no safety concerns from this intended use.

 In addition, the FDA is not aware of any study showing these food contact substances to be carcinogenic in humans.

The agency-initiated TOR exemption (TOR-2021-003) allows for the use of these substances in repeat-use applications without the requirement of an FCN.

 This slashes the number of duplicative submissions the agency receives for metal carbide and metal carbide alloy uses, which is consistent with its risk-based approach and conserves the resources for tackling issues of greater public health significance.