Angry Doctor

Wednesday, June 25, 2008

Real and Apparent Danger

There is a real and apparent danger in Singapore.

(emphasis mine)

Toxins in dish-washing detergent?

I WOULD like to ask why dish-washing liquid detergents do not carry ingredient labels. This is perhaps an oversight since such detergents leave traces on utensils, even after washing.

The danger is even more apparent in foodcourts where mass-washed utensils are coated with unknown ingredients.

Recently, there were reports about the danger of methylisothiazolinone, a neurotoxin that is found increasingly in shampoos, except some old, trusted brands. Methylisothiazolinone is possibly found in dish-washing detergent, especially those that tout 'anti-bacteria' formula since methylisothiazolinone is also a biocide.

Likewise, can the authorities clarify why formaldehyde is found increasingly in shampoos? The dangers of formaldehyde are already known, such as autism, eyesight degeneration and high carcinogenic effect on contact with water molecules. In addition, there are no standards as to how much formaldehyde is added to shampoo since it is considered a non-food item. But the danger is real and apparent.

Michael Yee

angry doc won't address the first part of Mr Yee's letter, since he too does not want detergent in his food. But the second part of the letter gets to him.

Formaldehyde is a widely used form of preservative. No doubt it can be fatal when ingested, and causes irritation of the eyes and skin when in vapour form (angry doc had personal experience of that back in medical school, he does - ah, sweet, gross anatomy!). But is it as dangerous as Mr Yee described?

Does formaldehyde cause eyesight degeneration? Well, yes, if it is splashed into your eye or injected into an eyeball.

Does it have high carcinogenic effect? Well, yes, it has been shown to cause some forms of cancers in mice, but it has not been shown to cause more cancers in people who are exposed to it at work (and who presumably use shampoo when they are off work).

Does it cause autism? angry doc couldn't find any evidence for that.

Mr Yee has given misleading information about the dangers of formaldehyde in the first part of that paragraph, but the penultimate sentence in that paragraph is simply untrure.

Shampoos are classified as cosmetic products, and come under the purview of the Cosmetics Control Unit of the Health Products Regulation Group of the Health Sciences Authority. The amount of formaldehyde permitted in shampoos is regulated by the ASEAN Cosmetic Directive, at the concentration of no more than 0.2%. Shampoos manufactured by Unilever contain formaldehyde of 0.04%. There is no evidence that at that concentration, application of formaldehyde to the skin for short durations causes any of the harmful effects Mr Yee mentioned.

Formaldehyde is a toxin in the commonly used sense of the word, but to say that shampoos can cause cancers, eyesight degeneration and autism, and that the authorities are not doing anything about it is dishonest and irresponsible.

The fact is information about regulations on the amount of formaldehyde permitted in shampoos and the dangers of formaldehyde is available on the internet if one would just search for them. Mr Yee had apparently not done so before sending in his alarmist letter, and the ST Forum editor has in angry doc's opinion lapsed in his duty by publishing it. This lack of editorial rigour is the real and apparent danger.

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  • Reminds me of the sodium lauryl sulphate scare some time back. Perhaps the editors of the forum page do not see it as their responsibility to vet such letters?

    By Anonymous Edgar, At June 26, 2008 11:15 am  

  • I am waiting for the day someone sends a letter to ST on the dangers of dihydrogen monoxide.

    By Blogger Lab Rat, At June 27, 2008 12:14 pm  

  • Dearest Angry Doc,
    I studied Brain Research/Neuropsychology at University. As an undergrad I was invited into an advanced graduate class that detailed how drugs affect the brain. We were taught then 25 yrs ago that when someone injests an alcohol drink that during the metabolic process the alcohol breaks down into formaldehyde which is stored in the eye. This is why alcoholics typically have eye issues, and that if one where to drink moonshine that is highly concentrated and pure then they could go blind quickly from this effect. I do not know how long the formaldehyde stays stored in the eyeball or how to detox from this. I you find out any information on this I would be interested. A friend of mine that is an artist has seen years working with a type of wood board that is easy to carve with a router for decorative purposes and he is now diagnosed with and eye disease called csr (Chorioserous rentinopathy?) He appears to be somewhat blinded by the fluid leaks near the retinal. I am wondering now about a link to formaldehyde toxicity and this eye disease.

    By Blogger Happy Camper, At July 03, 2009 9:51 pm  

  • Camper,

    Moonshine which contains methanol can cause blindness due to the toxic effect of its metabolite on the optic nerve.

    Eye diseases in chronic alcoholics seem to be multifactorial and relate to their nutritional status.

    I am not sure if central serous retinopathy is related to any form of chemical exposure though.

    By Blogger angry doc, At July 03, 2009 10:31 pm  

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