Semicarbazide used as a sealant in jar lids not a food safety risk

16 October 2003

Food Standards Australia New Zealand (FSANZ) believes that there is no evidence to suggest a food safety concern for any consumers, including infants, from the chemical semicarbazide. Semicarbazide has been found in Europe in some plastic sealing gaskets used in lids of foods packaged in glass jars and bottles.

Semicarbazide is a chemical which carries some potential for causing cancer in animals. It is believed that this substance may migrate from the plastic sealing gaskets used in the lids of glass food containing jars, however o nly very small quantities of semicarbazide may reach the food.

There are three types of sealing gaskets used in the lids of glass jars: a soft foamy type, a semi-foamy type and a hard type. These gaskets have been in use around the world for at least 30 years. Semicarbazide may be a by-product of chemicals used to manufacture the soft foamy and semi foamy types of gasket. The hard type of gasket is not linked to the possible occurrence of semicarbazide.

The European Food Safety Agency (EFSA), first issued advice on 28 July 2003, reporting that safety data available on semicarbazide is at present very limited. The available data suggests a potential for carcinogenicity in animals, but at much higher levels than reportedly found in foods. There is no evidence that semicarbazide causes cancer in humans and all the available toxicological data are insufficient to draw any firm conclusions. Studies have been commissioned by the EFSA in order to clarify some of the gaps in the available data.  

EFSA released a further statement on 15 October 2003 stating that “The risk to consumers resulting from the possible presence of semicarbazide in foods – if any – is judged to be very small, not only for adults but also for infants.   Although there are uncertainties in the risk assessment due to lack of full data at present, these relate only to how to assess what is considered to be a very small risk.”   Their full report can be found on http://www.efsa.eu.int

FSANZ   will continue to liaise with food regulatory authorities around the world to share the latest information on semicarbazide. However, FSANZ considers that even low levels of semicarbazide are not desirable in the food supply. FSANZ has met with the food industry and manufacturers of these sealants who have informed us that they are developing alternative methods of sealing glass jars. These new sealants will take some time to be developed and tested by industry before being used. This is to ensure that they are as effective as the previous type as sealant in preventing food from being contaminated by food poisoning bacteria.

No immediate action on the part of consumers or retailers is recommended regarding the occurrence of semicarbazide in any foods, including baby foods, packed in glass jars and bottles. In the meantime, FSANZ advice to consumers continues to be that there is not a food safety risk and that we should continue to eat a balanced diet including food packaged in glass containers.