A note about our rating system

feedback rating think dirty app

We got a lot of feedbacks since the launch about our methodology. Would like to share some of our thoughts and also some of the questions from reviewers.

Q. Why don’t you list percentage of chemicals?

Simply those information are considered trade secrets by manufacturers. The ingredient information we can obtain is from packages, and manufacturers are not required to list percentage on packages, unless they are considered drugs.

Q. Why do I see so many “dirty” ingredients? 

We rate BHA / BHT, PEGspetrochemicals, parabens, phthalates, formaldehyde releasing agents, siloxanessulfates, fragrance/parfum and non-biodegradable ingredients 10-8 Dirty. Because we believe those chemicals don’t belong in products we use daily, no matter how much or how little.

Some may argue low percentage is harmless. Then the debate will move from whether it’s safe or dangerous to how high or low percentage is dangerous.

Also for those we argue low dosage is ok, they simply forget the numbers of products we use, and also didn’t take into account of how each of the low dosage of controversial chemicals might react with each others. The debate on how much toxic chemicals should be in your products is similar to arguing how much MSG should be in your food. In both cases, we believe there shouldn’t be any.

Q. Why should I trust you? 

It’s a great question. Our answer to you would be then don’t trust the beauty counter advisor neither.

You should read all the sources we list and make your own judgement. Our rating is our opinions from sources we read. The reality is that there are clean products sold by conventional brands and dirty products sold by “natural” brands. The beauty of our app is we just look at the ingredients, and nothing else. When reviewing the ingredients, as citizen scientists, we form our opinions based on whether we would like that chemicals to be on our bodies from health and environment perspective – no matter what amount. The difference between us and other magazines judge their award winning products is that we read all the relevant science journals, government lists and non-profit groups’ reports. And most fashion magazine editors just go by what the advertisers’ talking points.

Here are our list of sources we referenced to:


Health Canada Hotlist

Canada Mandatory labelling

Environmental Defense Canada Toxic Ten

David Suzuki Foundation Dirty Dozen

Canadian Centre for Occupational Health & Safety

Ten Carcinogens in Toronto

Environment Canada Domestic Substance List


National Library of Medicine PubMed Studies

US Food and Drug Administration

Breast Cancer Fund Chemicals Linked to Breast Cancer

Campaign for Safe Cosmetics

Organic Consumer Association Top 10 to avoid

Center for Environmental Health 

Women’s Voice for the Earth

Cornell University Breast Cancer and Environmental Risk Ractors

Animal Derived Ingredients on PETA Beauty without Bunnies

CHE Toxicant and Disease Database

INCI Dictionary

National Toxicology Program

Proposition 65 The Safe Drinking Water and Toxic Enforcement Act of 1986

Center for Disease Control Registry of Toxic Chemicals

National Cancer Institute

Cosmetic Ingredient Review Assessment


European Union Health Commission CosIng  (Cosmetics Ingredients & Substances)



International Agency for Research on Cancer

Older Post Newer Post

Leave a comment

Please note, comments must be approved before they are published