The Food and Drug Administration (FDA) said the new rule would allow plants to modernise their equipment in keeping track of temperatures when manufacturing such heat-processed products.

Keeping accurate track of cooking and cooling temperatures is essential to the process, both in terms of the quality of the product and for food safety. Current rules only specify mercury-based thermometers.

"Under the proposal, these devices, which are the state-of-the-art equipment for measuring and recording temperatures, may be used instead of, or in addition to, conventional mercury-in-glass thermometers (MIGs)," the FDA stated.

The proposed rule would amend FDA's current regulations for the processing of low-acid canned foods such as beans, corn, peas, and potatoes, and clarify such requirements as recordkeeping and the rules for measuring and recording temperatures during processing.

The proposal also includes metric equivalents of the US avoirdupois measurements.

"This proposal is designed to benefit both consumers and the food industry," said Robert Brackett, the director of the FDA's Center for Food Safety and Nutrition. "It enables manufacturers to rapidly adopt technologically advanced temperature-indicating devices. And we believe that the proposed rule, after being finalized, would ensure that these devices are accurate."

The agency will allow low-acid canned food manufacturers who follow the proposed rule to change immediately from the currently required glass thermometers to the alternatives.

Although such devices remain out-of-compliance until the proposal is finalized, the FDA said it would consider, on a case-by-case basis, exercising its enforcement discretion if the new devices are used in a manner consistent with the proposed rule.

Processors who choose this option must comply with any revised requirements when the final rule becomes effective.

FDA is allowing a 90-day comment period on the proposed rule.