Methylchloroisothiazolinone (MCI) is a widely used insecticide that was developed in the 1970’s. MCI is used worldwide for control of mosquitoes, flies, ticks and fleas. Its main use today however is as a preservative in food packaging such as canned foods and fruit juices.
The chemical is considered safe for human consumption, but it does have some potential health risks. These include:
• Irritation of the eyes, skin and respiratory tract when inhaled or ingested. • Irritation of the liver and kidneys when swallowed or absorbed through the skin. • Infertility in women who are pregnant or breastfeeding. • An increased risk of cancer in children under five years old if they breathe in large amounts of MCI during their first year of life. • A decreased risk of birth defects in infants born to mothers who were exposed during pregnancy.
In addition, there are some possible side effects associated with long term exposure to MCI:
• Redness, swelling and itching at the site where it was applied. • Skin irritation when scratched or rubbed. • Eye problems including inflammation and conjunctivitis. • Liver damage may occur if consumed over time.
Although no direct link between exposure to this chemical and the development of cancer has been found, it may be that long-term exposure can speed up the growth of certain tumors. It is not clear whether or not it increases the risk of brain tumors.
In addition, large amounts of this substance can cause liver and kidney damage which may be fatal or, at the very least, require a liver or kidney transplant.
It should be noted that the World Health Organization has set an Acceptable Daily Intake or ADI for this chemical at 0-0.3mg/kg. This is the maximum amount per day that is considered safe for humans.
The following table shows how much of the preservative is allowed in certain foods by the US Food and Drug Administration (FDA). These limits were set to ensure that the FDA’s limit for daily intake is not exceeded.
Food Group ADI (mg/kg) Fruit Juice Concentrate 4.5 Beans 0.4 – 0.5 Olives 0.2 Pickles 0.2 Canned Fruits and Vegetables 0.2 Tomato products in brine (e.g.
canned tomatoes) 0.2 – 0.3 Tomato sauces 0.1 – 0.2
The following guidelines may be used to estimate the amount of this chemical that you may be exposed to if you eat a certain food:
FOOD GROUP MCI CONTENT (MG) Beans, canned 16 Canned Fruits, except mangoes and papayas 6 – 60 Mango puree 20 Papaya puree 55 Pickles, cucumber 5 Olives, ripe 8
It should be noted that the figures above assume that no water is added when cooking the food.
The amount of this chemical in a product is not always the same and can vary from batch to batch even if the source of the preservative is the same. There may be more in a product than what is mentioned above therefore it is always good to be cautious when eating foods preserved with this chemical.
The greatest concern is for infants who might consume a lot more food relative to their body weight.
So what can you do to limit the amount of this chemical that you are exposed to?
The following guidelines may be helpful:
• Try to avoid canned food if possible. Fresh or frozen is best. Canned food tends to have more preservatives and less nutrients than frozen or fresh foods. When canned food is necessary, try to stick with those foods where this chemical is not the main preservative such as tomato paste, fruit juice or fruit puree.
• Always rinse canned food before cooking or eating to reduce the amount of this chemical that you might consume. This is especially true for fruits and vegetables. Rinsing also helps reduce the sodium content of canned goods which is typically very high.
• Do not keep canned food longer than a year. Bacteria tend to thrive more as the can rusts which can lead to serious health issues.
In closing, BPA is just one of several chemicals that you may be exposed to on a daily basis. While health concerns have been raised over this chemical and others, very little is understood about the long-term effects of most chemicals on our health. It is always best to play it safe especially when dealing with foods that are primarily meant for consumption by infants and young children whose bodies are still developing.
Sources & references used in this article:
Comparative evaluation of antimicrobials for textile applications by L Windler, M Height, B Nowack – Environment international, 2013 – Elsevier
FC01. 1 Occupational contact dermatitis from methylisothiazolinone by M Isaksson, B Gruvberger, M Bruze – Contact Dermatitis, 2004 – Wiley Online Library
Topical nonsteroidal antiinflammatory drugs: allergic and photoallergic contact dermatitis and phototoxicity by S Ophaswongse, H Maibach – Contact dermatitis, 1993 – Wiley Online Library
Artificial preservatives and their harmful effects: looking toward nature for safer alternatives by SP Anand, N Sati – International journal of pharmaceutical sciences and …, 2013 – Citeseer