The Consumer Council has found wide variances in the safety level of progressive hair dyes available to consumers in Hong Kong.
The test revealed that the sample with the highest level (2.5%) of the dye agent lead acetate contained some five times more than the sample with the least amount (0.47%) of the chemical.
Excessive lead exposure by the human is known to damage the nervous system, red blood cells and kidneys. Other undesirable health effects include decreased co-ordination and mental abilities.
The effects of lead exposure can be treated and reversed, but if no treatment is given, permanent brain damage can result.
The test showed that the eight samples in the test varied in their content of lead acetate - two were under 1%, one at 1%, two at above 1% and one above 2%. The two samples undetected with lead acetate were found to use another dye agent silver nitrate.
In Hong Kong, the Pharmacy and Poisons Ordinance regulates medicinal products with more than 4% lead acetate. As the progressive hair dyes contain less than 4% lead acetate, they are not regulated by the Pharmacy and Poisons Ordinance.
Among the samples with lead acetate, three were found to have lead levels in excess of the requirements of the Mainland, the European Community, the USA and/or Canada.
The test findings have prompted the Department of Health to study hair dyes with less than 4% of the chemical with other relevant government departments. On conclusion of the study, the Department will then consider whether it is necessary to control these products.
The two samples with silver nitrate were found to contain 1.3% and 1.4% of the chemical respectively.
The US Food and Drug Administration does not permit the use of silver nitrate in hair dyes on the basis of findings that solutions of silver salts greater than 1% concentration could cause severe damage to the eye.
According to the authoritative "Pharmacology in Medicine", silver nitrate solution, even as a 1% solution, must be used with caution since damage cauterization (the process of destroying issue) of cornea may result especially with repeated applications as in the case of hair dye usage.
Besides the US FDA, the Mainland PRC's Standard GB7916-87 and European Community Directive 76/768/EEC also do not recommend the use of silver nitrate in products intended for the hair.
Consumers using hair dyes with silver nitrate are urged to take great caution to avoid any contact with the eye. And never attempt to dye eyelashes and eyebrows with these products or for that matter products with lead acetate.
According to Health Canada, any cosmetic containing silver and/or silver salts must bear the following warning: This product contains silver and/or silver salts. Avoid contact with broken or abraded skin.
Both samples made no disclosure of the silver nitrate contents, and the Council has forwarded the findings to the Customs and Excise Department. Under the General Safety Requirements of the Consumer Goods Safety Ordinance, the Department has taken follow-up action on the lack of proper labelling of the products concerned.
The Government is also urged to consider adopting the standards of the European Community, the Mainland and the US not to allow use of silver nitrate in such dyes.
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