Health effects of MethylisothiazolinoneMIT is a common biocide and preservative used in industrial and household products such as shampoos, toothpastes, soaps and other body care products. Also MIT is used in dehumidifiers so it can be detected in air conditioned indoor air. When it was introduced in the market as an ingredient of cosmetics and personal care products there were no studies testing in any way its safety.

This changed in 2002 when the first study by Dr Shen Du from the University of Pittsburg was published and reported that MIT displays strong neurotoxic and cytotoxic properties in vitro; this means that cells and specifically neural (brain) cells die, upon exposure to MIT. This specific research was done in cell cultures, not live animals and rather large doses of MIT were used but the results were very impressive (and sad), cells sustained extensive injuries and MIT-induced cell death.

Another study in 2004 from the same research group tried to simulate chronic exposure to MIT, like the one most of us probably have sustained while using toothpastes, hair dyes and shampoos containing small doses of MIT for prolonged period of time. MIT was found to inhibit proper growth and development of neurons. Imagine the potential damage unborn babies are subjected to because the mother shampoos her hair or brushes her teeth with MIT loaded products. In the study, the length of neural axis only managed to reach half of the total length it reached without MIT; this could mean fewer synapses (connections between neural cells) and limited brain development for the newborn. Bear in mind that all the neural cells we have are created while in our mother’s womb, no new cells are created once we are born. The development of the brain after that stage is basically a matter of creating and establishing new neural networks which is translated as learning new skills and storing memories. I don’t even dare to think of how much brain power the last generation may have lost from this chronic, debilitating poisoning it has been subjected to.

Both publications presented were published in peer-reviewed scientific journals and are available to download for free through the following links.

Du et al, 2002

He et al, 2004

Despite the above research that should at least create some doubts about the safety of MIT in air conditioners and cosmetics, MIT is still considered safe and that there is not enough evidence about it not being safe. This story is very old and we have seen it for many dangerous chemicals in widely used products. I honestly don’t understand how people who are supposed to be responsible for protecting public health compromise with their decisions the wellbeing of millions. Animal studies are acceptable when a new toxic drug is tested and needs approval to go to the next stage of clinical trials; but this is not the case for neurotoxins which poison babies, children and adults all their lives, animal studies are certainly not enough in this case…. Regulatory authorities in the USA, Japan and Europe and more than 25 other countries have all independently concluded the product is safe. CFTA (Cosmetic, Toiletry and Fragrance Association) respondes:

The abstract on Methylisothiazolinone (MI), presented at the Cell Biology 2004 meeting of the American Society for Cell Biology (ASCB) lacks a credible scientific basis in suggesting that MI could be a safety issue for consumers using personal care products (emphasis added). In determining the safety of any ingredient, a major factor is exposure. Cosmetic exposure is so much lower than what is presented in this abstract as to make the study meaningless for safety evaluation purposes regarding cosmetic products.

This is exactly the type of reasoning that has led to a world where newborn babies are already contaminated with more than 300 chemicals… Common sense and corporate accountability would suggest that the experiments in Pittsburg, should be the trigger for more experiments to be designed and funded in order to properly clarify and establish whether MIT is safe or not. This hasn’t happened of course and at the moment there are hundreds of widely used products out there which may be poisoning our brains. Chances are that they do that indeed. You dont have to be a rocket scientist to suspect that something poisoning cells is probably going to be quite harmful for the whole body and it will keep on poisoning the same cells once it is inside the body!

A basic list of products containing MIT follows. It is by no means extensive or complete so do your own research. As always,  I have one piece of golden advice: Read the Labels!

A tool which you will find awesomely useful in your quest for natural, toxic-free cosmetics is Skindeep, a massive online database of personal care products with all their ingredients listed. With this tool you can interrogate the products you use already to check if they have any toxic inside and if yes, you can find safer products to use instead.

You may also want to read about a declared carcinogen (aka cocamide diethanolamine (cocamide DEA)), which was recently found in almost 100 popular shampoos and soaps.

Soap Bars

Camay soap bar

Dove soap bar with ¼ moisturizing lotion

Oil of Olay bar soap for soft moisturized skin

Body Baths

Vaseline Intensive Care foaming crème bath, Botanical Garden

Vaseline Intensive Care Moisturizing Bath and Body oil

Vaseline Intensive Care Moisturizing Bath Beads Enriched with Aloe

Vaseline Intensive Care Moisturizing Bath Beads Peaceful Orchard

Vaseline Intensive Care Moisturizing Bath Beads Petal Soft

Vaseline Intensive Care Moisturizing Bath Beads Vitamin E

Vaseline Intensive Care Soft Petal Foaming Crème Bath

Dove Sensitive Skin Moisturizing Body Wash

Dove Ultra Moisturizing Body Wash

Vaseline Intensive Care Moisturizing Body Wash

Hair Conditioners

Clairol Herbal Essences Conditioner-Fine/Limp Hair

Clairol Intensive Blends Conditioners (4 types)

Pantene Pro V Color Revival Conditioner

Pantene Pro V Constant Care Conditioner

Pantene Pro V Deep Hydrating Treatment

Pantene Pro V Detangle Light Spray Conditioner

Pantene Pro V Essentials Hair Revival Cream

Pantene Pro V Essentials Instant Hair Quencher

Pantene Pro V Hydrating curls conditioner

Pantene Pro V Sheer Volume Conditioner

Pantene Pro V Smooth & Sleek Conditioner

Pantene Pro V: Provitamin Daily Treatment & Conditioner – Fine Hair

Pantene Pro V: Provitamin Daily Treatment Conditioner Dry Hair

Salon Selectives Conditioner Type P Protective

Salon Selectives Conditioner Type M Moisturizing

Vida Sassoon Conditioning Rinse- Stylists Choice

Hair Styling Products

Clairol 3 in 1 Mousse Maximum hold

LOreal Pumping Curls for Culry Hair

Pantene Pro V Ready, Set Curl Reviving Treatment

Pantene Pro V: (Alcohol Free) Styling Mousse Extra

Vidal Sassoon Alcohol Free Styling Gel Extra Hold

Vidal Sassoon Alcohol Free Styling Mousse Extra Body

Clairol 3 in 1 Condition Hairspray Extra Hold, unscented, Aerosol

Clairol Final Net all Day Hold Hairspray – Regular

Pantene Pro V Essentials Natural Body Booster Spray

Pantene Pro V Hold & Protect Non Aerosol Hairspray

Pantene Pro V Settique (the whole group of Aerosol and non Aerosol sprays)

Pantene Pro V Settique Hold & Protect with Colorshine

Pantene Pro V Shine on Glossing Spray with Colorshine

Pantene Pro V: Provitamin Wet/Dry Styling Hold Spray

Vidal Sassoon Alcohol Free spray on Gel-Extra hold

Vidal Sassoon Non Aerosol Finishing Hair Spray Ext


Clairol herbal Essences Intensive Blends Replenishing Shampoo

Clairol herbal Essences Shampoo- Fine/Limp Hair

Clairol herbal Essences Shampoo- Normal Hair

Clairol Intensive Blends Moisturizing Shampoo for Normal Hair

Clairol Intensive Blends Shampoo Protecting for Colored/Permed Hair

Pantene Pro V Classically Clean Shampoo

Pantene Pro V Essentials, Daily Strengthening Complex-1

Pantene Pro V Essentials, Daily Strengthening Complex-2

Pantene Pro V Hydrating curls shampoo

Pantene Pro V Purity Clarifying Shampoo

Pantene Pro V Sheer Volume Shampoo

Pantene Pro V Smooth and Sleek Shampoo

Salon Selectives Botanical Blends Shampoo: Aloe

Salon Selectives Shampoo Level 1: Frequent Use

Salon Selectives Shampoo Level 4: Extra Moisturizing

Salon Selectives Shampoo Level 5: Regular-Normal

Hair Dyes

Clairol Herbal Essences, True Intense Color

Clairol Hydrience Permanent Hair Color

Clairol Revitalique Permanent Hair Color

Garnier Nutrisse Permanent Crème Haircolor

Grecian Formula

LOreal Feria Haircolor

LOreal Open Haircolor

LOreal Preference Haircolor

Revlon High Dimension 10 Minute Permanent Haircolor





Colgate (Baking Soda, kids, Tartar control, total)

Crest (Cavity Protection, Extra Whitening, Multi Care, Rejuvenating Effects, Sensitivity Protection, Tartar Control)

Sensodyne (Anticavity, Extra Whitening)

Baby Products

Johnsons Baby Bath

Johnsons Baby Bedtime

Johnsons Baby Soothing Vapor Bath

Johnsons Moisturizing Baby Bath

Johnsons Baby soap Bar

Johnsons Baby Shampoo

Johnsons kids Head to Toe

Johnsons Baby Lotion

Johnsons Baby oil

Vaseline Nursery Jelly

Vaseline Petroleum Jelly