The law implements EU regulations setting transitional migration limits for plasticisers in lid gaskets.
The proposed law also sets out penalties, including the possibility that a firm's managers could face up to two years in prison, a fine or both, for breaking the law.
The proposed legislation is in part a response to the findings in 2003 that the chemical semicarbazide had been migrating from gaskets into foods.
Semicarbazide is a by-product of plastic seals used on the inside of metal twist-on-twist-off lids of glass jars that contain food.
European Regulation (EC) No. 372/2007 on materials and articles in contact with food came into force on 22 April 2007 and is applicable until 30 June 2008.
It lays down transitional migration limits for plasticisers in gaskets in lids used for food products.
Gaskets in lids intended to come into contact with food fall under the scope of the plastics Directive 2002/72/EC, as amended.
However, that directive applies to materials and articles that consist exclusively of plastics or are composed of two or more layers of plastics.
The transitional law is needed as gaskets in metal lids are not covered by that directive.
"Consequently, there are separate rules across Member States that may pose a barrier to trade," the UK's Food Standards Agency stated in issuing the proposed leglislation.
"As such, it has been necessary to clarify the position regarding gaskets in lids and fix transitional specific migration limits (SML)."
SMLs will apply to the sum of a number of plasticisers used in gaskets in lids coming into contact with fatty foods and permit the free circulation of those products affected.
Lids and foods that pose a significant risk are immediately excluded from the market, under the directive.
The European transitional regulation is also meant to provide industry with sufficient time to develop gaskets that are compliant with the SML laid down in Directive 2002/72/EC, as amended by Directive 2007/19/EC.
The plasticisers covered under the transitional laws include epoxidised soybean oil (ESBO), acetylated mono- and diglycerides of fatty acids, polyester of adipic acid with glycerol or pentaerthritol, esters and even numbered, unbranched C12- C22 fatty acids, tri-n-butyl citrate, glycerol monolaurate diacetate and 12-(Acetoxy) stearic acid, 2,3-bis(acetoxy)-propyl ester, polyesters of 1,2-propanediol or 1,3- and/or 1,4-butanediol or polypropylene-glycol with adipic acid, and end-capped with acetic acid or fatty acids C12-C18 or n-octanol or n-decanol.
The deadline for comments is 10 August 2007.