20 May 2011
A recent newspaper article (Sydney Morning Herald 18 May 2011) highlighted an increase in the number of food poisoning cases linked to raw eggs.
The article discussed the issue of refrigeration and said that Food Standards Australia New Zealand (FSANZ) had “quietly introduced changes to the food standards code, omitting any regulations related to temperature control”.
FSANZ has been working on the primary production and processing standard for eggs for a number of years; work that has involved a thorough risk assessment of egg production and processing in Australia and extensive consultation with industry, scientists, government agencies and the public. The work was also undertaken with the assistance of international and domestic experts.
The new standard places legal obligations on egg producers and processors to identify and control food safety hazards associated with the production and processing of eggs, e.g. minimising the contamination of feed with Salmonella so it is not introduced to the laying flock.
It will work together with existing requirements on food businesses to ensure safe handling and preparation of food for sale.
Unlike many other countries, the types of Salmonella that can contaminate the inside of eggs as they are formed in the bird are not present in Australian laying flocks. While Salmonella can be sometimes present on the outside of eggs, it won’t grow, even at room temperatures, because the condition of the egg surface limits its growth.
To be able to grow, Salmonella needs to pass through the cuticle (protective coating) and egg shell, membranes separating the egg components, survive the hostile environment of the egg white and enter the egg yolk.
During its risk assessment FSANZ examined the issue of refrigeration of eggs and this included considering a 2004 Australian Egg Corporation Limited report that recommended refrigeration of eggs throughout the supply chain.
Our review of reported food poisoning outbreaks associated with eggs in Australia indicated that most cases were attributed to consumption of uncooked or lightly-cooked foods containing contaminated raw egg, for example sauces and desserts. It is generally very hard to pin-point an exact source of contamination in outbreaks associated with mixed foods such as these.
Factors that may have contributed to outbreaks included cross-contamination during food preparation (i.e. transfer of Salmonella from the surface of the egg to other surfaces and/or foods) and storage of the food containing raw egg at temperatures that would permit growth of Salmonella (greater than 7°C).
While we acknowledge that refrigeration during retail storage may enhance the quality of eggs, this option was excluded early in the standard development process due to the nature of egg shell contamination in Australia and the substantial cost of implementing such an option.
Full details about the standard including risk assessment reports can be found here