Sulfites represent a group of chemicals [such as sodium and potassium sulfites, bisulfites, metabisulfites and sulphur dioxide (SO2)] and are widely used as a preservative/ additives in food, pharmaceutical and cosmetic industry. Sulfites react with water and cause release of sulfur dioxide gas, an unpleasant gas that can trigger broncho-constriction and breathing difficulties. Clinical symptoms of sulfites exposure principally occur from the consumption in foods and drinks or through the use of pharmaceutical and cosmetic products in consumers and professionals. The ingestion or inhalation of sulfites and its additives has been reported to induce a range of clinical effects in sensitive individuals, ranging from dermatitis, urticaria, and gastrointestinal discomfort (abdominal pain and diarrhoea), anaphylactic and asthmatic reactions.

Skin and respiratory tract reactions are commonly accounted for the majority of cases of sulfite sensitivity. The common symptoms include skin irritation, allergy, breathing difficulties, irritation and constriction of airways. The first case report of irritation of the respiratory tract followed by sulfites ingestion was published in 1973. Subsequently, a number of reports have been documented on respiratory hyper-sensitivity due to sulfites. Majority of the studies suggest that asthmatic responses to sulfites in sensitive people are generally agreed between 3% -10%. However, studies also report that as many as 30% cases of sulfite sensitivity occur in individuals with no known history of asthma and sulfites sensitivity may be more common among women and children. Laboratory and human studies raised serious concerns on the use of sulfites, in this respect in 1986, U.S. Food and Drug administration (FDA) has banned the use of Sulfites as preservatives in food and vegetables.

Asthmatic response and chronic skin symptoms due to exposure to sodium bisulphate and metabisulfite has also been reported in occupational settings. These studies suggested that people in occupation setting are at greater risk of increased incidence of asthma and persistent skin symptoms as a consequence of repeated exposure of sulfites. Inorganic sulfites and bisulfites, such as sodium, ammonium and potassium sulfites are generally used at a concentration above the threshold level of recommended sensitive concentration in hair colors and bleaches. Prevalence of cases of skin sensitivity due to local or occupational exposure of potassium and sodium metabisulfite (used frequently in hair color and bleaching agent) has arisen largely during the recent past. In cosmetics, sulfites are used frequently in hair colors and bleaches, creams and perfumes, skin fading/lighteners, false tan lotions, anti-ageing creams, moisturisers, and facial cleansers. Skin and allergic reactions are more common among the hair style professionals and consumers. According to one survey ~15%-80% stylists suffered from allergic reactions. Research studies now suggest sulfites as immune system toxins, which can cause allergic reactions predominantly in asthmatic people. (When stylists are mixing hair lighteners, they should be careful not to inhale the powder before mixing in the developer.)

The wide spread use of sulfites and the rising incidence of sulfite sensitivity in cosmetic industry (especially in hair colors and bleaches) could pose serious risk to consumers as well as professionals. These, studies raise a serious concern regarding the suitability of using sulfite additives in cosmetic products. Consumers and professionals should be aware with clinical manifestations of sulfites sensitivities and should not underestimate these chemicals. It’s up to you, whether to go along with the silent health hazard or become aware of the health issues associated by the use of certain chemicals.

References:

Aalto-Korte, K., K. Suuronen, et al. (2009). “Sodium metabisulfite – a contact allergen?” Contact Dermatitis 60(2): 115-117.

Davies, R. F. and G. A. Johnston (2011). “New and emerging cosmetic allergens.” Clin Dermatol 29(3): 311-315.

Lee, A. and R. Nixon (2001). “Occupational skin disease in hairdressers.” Australas J Dermatol 42(1): 1-6; quiz 7-8.

Lester, M. R. (1995). “Sulfite sensitivity: significance in human health.” J Am Coll Nutr 14(3): 229-232.

Madan, V. and M. H. Beck (2009). “Sodium metabisulfite–a contact allergen?” Contact Dermatitis 61(1): 58.

Vally, H., N. L. Misso, et al. (2009). “Clinical effects of sulphite additives.” Clin Exp Allergy 39(11): 1643-1651.

White, I. R. (2006). “Second cite. Contact allergy to hair dyes is a well-recognized problem.” Clin Exp Dermatol 31(5): 724-726.