Free Shipping on orders $75+ (US)

What is Think Dirty methodology?

Posted on August 04 2015

think dirty® methodology

Think Dirty® is committed to helping consumers identify the potential risks associated with the personal care products they use every day. Unlike other ingredient databases, we focus exclusively on the chemical content of the products in question. We have consciously avoided the widely-used practice of “greenwashing”, whereby the environmental or social responsibility of a product’s manufacturer is factored into the assessment allowing a product to receive an artificially low toxicity rating. We are solely concerned about the possible impact of a given product on an individual’s health, and our ratings methodology reflects that singular commitment.

Our ratings are determined based on publicly available data released by non-profit and government agencies in North America regarding the health and safety of the individual components found in your personal care products. A list of our data sources can be found in Appendix A.

We assess the overall risk of a given product based on the potential health impacts of its published ingredients. Each ingredient listed on the product label or manufacturer’s website is evaluated for documented evidence of Carcinogenicity, Developmental & Reproductive Toxicity and/or Allergenicity & Immunotoxicity, as show in the table below.

Evaluations are performed by Think Dirty’s Founder and Advisory Board, all of whom have extensive experience in relevant fields such as Medicine, Biochemistry, Biology, Physiology, Environmental Toxicology, Environmental Health & Safety and Chemical Engineering, and a track record of working with Health Canada, the US Food & Drug Administration, the European Medicines Agency, Environment Canada, the US Environmental Protection Agency and other related government and not-for-profit agencies.

By default, products receive an overall Think Dirty® rating no lower than the highest rating of any individual ingredient. If several ingredients in a given product receive high ratings, the product itself is automatically assigned a Think Dirty® rating of 10. It is important to note that even though some of the ingredients in personal care products may be present in very small quantities, the likelihood of significant repeated exposure is high due to the frequency with which personal care products are typically used. It is widely acknowledged that even low-level exposure to known toxins can have deleterious effects on human health if the exposure is repeated and long-term.

In some cases manufacturers choose to define a component or group of components as proprietary and therefore confidential, in which case the specific ingredients in that component are not publicly disclosed and cannot be evaluated using existing health and safety data. This is a particular issue with an ingredient found on many personal care products, which is simply listed as “fragrance”. The sidebar below describes the significant potential health risks associated with “fragrance”, and our approach to rating products that contain this inscrutable ingredient.


In recognition of some manufacturers who chose to voluntarily submit their products for rigorous third parties certifiers such as USDA Organic, ECO Cert and NSF. We are in the process of rating these certified products with more positive rating than the products with same ingredients but not certified.

The Think Dirty® Product Rating Scale, Dirty Meter™ is defined in the table below.

 (please visit their link below to see table)



Sold Out