For asthma sufferers:the facts about sulphites in food
What are sulphites?
Sulphites, including bisulphites, metabisulphites and sulphur dioxide are permitted as food additives in Australia and New Zealand by the Food Standards Code which is developed and maintained by Foodstandards Australia New Zealand (FSANZ).
Sulphites are a normal product of metabolism, and are naturally present in the body. Sulphites are also produced by microorganisms and are present in small quantities in many foods even where none has been added.
Sulphur dioxide gas remains a major pollutant in some urban areas. This results from the burning of fossil fuels.
Sulphites are also used to preserve some medicines.
Why are sulphites added to foods?
Sulphites are added to foods for many different reasons. The major functions that sulphites perform in foods are preservation and inhibition of browning reactions.
Sulphites act as preservatives by slowing down the growth of microorganisms that could otherwise spoil foods. Sausages and frankfurters for example, are permitted to contain sulphites to prolong their shelf-life prior to cooking.
The cut surfaces of peeled and sliced fruits and vegetables can turn brown. Exposing the cut surfaces to sulphite solutions can delay the onset of this discolouration. Frozen potato chips and dried apricots may contain sulphites to maintain colour.
Sulphites may also be used as processing aids, such as for sterilising bottles prior to packaging food or drink.
Are sulphites safe?
In recent years international scientific committees have thoroughly investigated the safety of sulphites. These investigations concluded that, for most people, sulphites in foods present no risk to public health and safety.
However, a small section of the population responds to sulphites with allergy-like reactions - these are mainly people who suffer from asthma. In sulphite-sensitive people, sulphites can provoke asthma and other symptoms of an allergic response such as skin rashes and irritations.
Sensitivity to sulphites in food is dependent on how much a person is exposed to sulphur dioxide or sulphites from all sources.
Who should be alerted to sulphites in foods?
All people with asthma should be wary of those foods which may contain high levels of sulphites.
Some asthma sufferers are sensitive to sulphites in food. Research indicates that sulphur dioxide gas can provoke asthma in sulphite-sensitive people when it is inhaled. In most foods to which sulphite is added, some of the sulphite in the food exists as sulphur dioxide gas. So, as foods are eaten, sulphur dioxide may be inhaled. Clinical studies have shown that in sulphite-sensitive people, the level of sulphite which provokes asthma varies greatly between people.
Sulphites must be declared in the statement of ingredients when present in foods in concentrations of 10 mg/kg or more as an ingredient; or an ingredient of a compound ingredient; or a food additive or component of a food additive; or a processing aid or component of a processing aid. Sulphites must be labelled by their class name, followed by the additive's specific name or code number (220 to 228). For example, the ingredient list on a carton of orange juice may state: 'orange juice, sugar, preservative (223)'.
For detailed information on the Australian Food Additive numbering system, see the FSANZ booklet The Official Shopper's Guide to Food Additives and Labels which is available on the FSANZ website www.foodstandards.gov.au
There are a few foods which are permitted to contain sulphur dioxide and have been implicated in reports of asthma. These include some types of:
- fruit juice or drink;
- wine;
- dried tree fruit; and
- delicatessen meats.
What should people do if they think they could be sensitive to sulphites?
People with severe asthma are advised to always carry asthma preventer and reliever medication prescribed by their doctor. They should avoid eating foods that declare the addition of sulphites in the ingredient list.
While packaged foods are required by the Food Standards Code to carry an ingredient list, unpackaged foods are not. Restaurant meals and take-away foods for example, are not required to have a list of ingredients. However, a declaration of the presence of sulphites in concentrations of 10mg/kg or more must be provided either by a sign displayed on or in connection with the display of the food or provided either verbally or in writing upon the request of the purchaser.
Sulphite-sensitive consumers should be aware that unpackaged processed foods may contain the same additives as their packaged counterparts.
For information about asthma - The Asthma Foundations of Australia-
Asthma Association of the ACT Inc.
| Asthma Foundation of Northern Territory |
Asthma Foundation of NSW
| Asthma Foundation of Queensland PO Box 394 FORTITUDE VALLEY QUEENSLAND 4006 Telephone (07) 3252 7677 |
Asthma Foundation of South Australia
| Asthma Foundation of Tasmania 82 Hampden Road BATTERY POINT TASMANIA 7004 Telephone (03) 6223 7725 |
Asthma Foundation of Victoria | Asthma Foundation of Western Australia |
For information about sulphites in food -
Foodstandards Australia New Zealand
PO Box 7186
CANBERRA B C A C T 2610
Telephone (02) 6271 2222 Fax (02) 6271 2278
State and Territory Health Authorities
| ACT Health Protection Services Frewin Place SCULLIN A C T 2614 Telephone (02) 6205 1700 | Department of Community & Health Services |
Environmental Health Services of Western Australia
| Victorian Department of Human Services Food & Water Unit GPO Box 4057 MELBOURNE VICTORIA 3000 Telephone (03) 9637 4094 |
NSW Health Department | South Australian Health Commission
|
| Queensland Health GPO Box 48 BRISBANE QUEENSLAND 4001 Telephone (07) 3234 0952 | Territory Health Services |