Methodology

The GoodGuide rating methodology is grounded in ingredient hazards, context of use, data adequacy, and the source and extent of information received about a product (i.e. full formulation and 3rd party certifications). We identify methods that are widely accepted and science-based that can be used to define the intrinsic chemical hazard of products.

Selecting Products to Rate

GoodGuide focuses on rating everyday household consumer products bought either from brick and mortar stores or online retail outlets like supermarkets or e-commerce sites. Our core product categories are personal care, cosmetics, and household chemicals.

We use a variety of sources to add to our catalogue of available products, identify relevant brands and companies and collect information about product attributes required for our ratings system. While the GoodGuide team generally makes these determinations, product manufacturers and brand companies can request to have product(s) added or removed from the website; consumers who join the GoodGuide community as registered users can also request product(s) to be added.

Rating System Design for Personal Care, Cosmetics and Household Chemicals

Our current standard of practice screens product ingredients against GoodGuide expert-selected authoritative and governmental lists relevant to assessing hazards. Our endpoints for ingredient evaluations include lists that are aggregated from authoritative regional (i.e. ECHA), national (FDA) and pan-national (i.e. OECD) government regulatory lists maintained by Organization for Economic Co-operation and Development (OECD) member countries.

GoodGuide maps the ingredient hazard information from these lists to 14 separate hazard endpoints that are considered in the hazard scoring.

  1. Asthmagen
  2. Carcinogenicity
  3. Developmental Toxicity
  4. Reproductive Toxicity
  5. Cardiovascular/Blood Toxicity
  6. Gastrointestinal/Liver Toxicity
  7. Immunotoxins
  8. Kidney Toxicity
  9. Musculoskeletal Toxicity
  10. Neurotoxicity
  11. Endocrine Disruptors
  12. Genotoxins
  13. Sensitizers
  14. Acute Oral and Inhalation Toxicity

GoodGuide counts the number of ingredients in each product that are categorized as low-, medium- or high-hazard. An example of a low hazard is a low toxicity when ingested while a high hazard is a known carcinogen. We then factor in additional negative information (such as regulatory restrictions) and any available positive information (such as third-party certifications) to assign product ratings.

To rate a personal care, cosmetic and household chemical product, GoodGuide considers the following attributes:

  • An intrinsic hazard rating based on the number of product ingredients categorized as low-, medium- or high-hazard concerns.
  • Review as to whether the product contains substances that are banned or restricted for use in countries other than the U.S. ex. what’s ok in leave-on cosmetics in the U.S. may not be ok in Europe or Canada or Japan, etc., etc.)
  • Indicators that the product is among the best on the market in its category (e.g., has the product been certified for health impacts by a credible third-party).
  • Indicators of data gaps that preclude evaluation of the product (e.g., no or inadequate disclosure of product ingredients).

Categorizing Ingredients by Levels of Intrinsic Hazard for Personal Care, Cosmetics, and Household Cleaners

An ingredient scores as no hazard level if:

  • The ingredient has no known or established toxicity data. (Note: The score will be adjusted for data adequacy before providing a final score); and,
  • It is not on any of the GoodGuide lists of toxic chemicals which has suspected or known intrinsic hazards; and,
  • It has not been detected in human tissue or urine; it is not a high production volume chemical that lacks safety data.

An ingredient scores as a low level hazard if:

  • It exhibits two or less suspected intrinsic hazards; and/or
  • It has a relatively low toxic potency for inhalation and ingestion exposures; and/or
  • It is only occasionally detected in human tissue or urine; and/or

An ingredient scores as a medium hazard level if:

  • It exhibits three or more suspected intrinsic hazards effects; and/or
  • It has a relatively moderate toxic potency for inhalation and ingestion exposures; and/or
  • It is regularly detected in human tissue or urine.

An ingredient scores as a high level hazard if:

  • It exhibits one or more known intrinsic hazards; and/or
  • It has a relatively high toxic potency for inhalation and ingestion exposures; and/or
  • It is frequently detected in human tissue or urine.

Data Availability

Data availability is one of the most important criteria for selecting what matters in regard to GoodGuide scoring. In order to ensure we have comparable information available for rating products, we require that scoring information is publicly available for the majority of rated products. Data availability influences the GoodGuide rating system in two important ways:

  • In many cases, data availability considerations require GoodGuide to rely on “screening-level” information rather than “data-intensive” information. In a world of perfect data sets, for example, product ratings would be based on detailed risk assessments that combine information about the hazards of ingredients with data characterizing consumer exposure to those chemicals. Unfortunately, these data are seldom available in public sources, so GoodGuide utilizes more readily ascertainable hazard information like the number of ingredients in a product which is available to the public through labels. In some cases, manufacturers have made complete product formulations, risk assessments, clinical studies and other scientific product assessment information directly available to GoodGuide. It is important to note that GoodGuide permits and encourages manufacturers to supply any pertinent data to us. You will see this noted on the product page as “Manufacturer disclosed. GoodGuide rated”.

  • Because lack of transparency about product attributes often hinders the public's ability to evaluate hazards, GoodGuide has created several other methods to track data availability and ultimately impact product ratings. At the product level, GoodGuide tracks whether the specific data elements that are needed to assess a product's hazards are public. Personal care, cosmetic or household chemical products missing complete ingredient lists are penalized in our scoring system because these products lack the data needed to assess chemical safety. Conversely products where manufacturers have shared data to GoodGuide scoring may reflect a higher score. In the GoodGuide scoring system, manufacturer transparency may equate to a higher overall rating.

Adjusting Scores to Account for Data Gaps

GoodGuide adjusts a product's hazard score if information is missing that is required to evaluate its potential impact.

Our hazard evaluation requires a complete list of a product's ingredients (with sufficient detail about chemical identity to allow ingredients to be checked against authoritative hazard lists) and information about the percent composition of a product (to characterize potential exposures and evaluate compliance with regulatory restrictions). Unfortunately, manufacturers seldom publicly provide both of these types of information for most consumer products. There are instances where manufacturers have provided this information to GoodGuide. You will see that indicated on the product page as “Manufacturer Disclosed. GoodGuide Rated”.

Adjustment for products that lack full ingredient data

For household chemical products, there is no current regulatory requirement that companies disclose full ingredient lists. For personal care products, ingredient disclosure is required, although it may include generic ingredient names that are not specific enough to support hazard evaluation. To create an incentive for full ingredient disclosure, GoodGuide caps a product's score if it lacks complete ingredient data or lists generic names that do not support chemical-specific evaluations. The caps applied are described in the following table:

Score Cap Amount of Ingredient Information Available
0 If no information is available
6 If formulation does not include a full list of ingredients and uses generic ingredient names or lists “fragrances” without further characterization
7 This is for household products only. If the product is a household product and if the manufacturer has not provided GoodGuide with detailed product formulation information or has not participated in third-party certification programs a score will never exceed a 7. For example, unlike cosmetics and personal care products, under current U.S. federal regulations, household products are not required to list all ingredients on their product labels. For this reason, GoodGuide cannot get public and adequate data on household products like it can for cosmetics/personal care products
10 If all ingredients are disclosed either to the general public for personal care products or to GoodGuide for internal verification that the maximum concentration of generically identified ingredients falls below a recognized acceptable level or shows no hazard potential at concentrations used; or all ingredients reviewed and approved as part of a credible third-party certification.

Adjustment for products that lack percent composition data

For household chemical products and most personal care and cosmetic products (with the exception of sunscreens), there is no current regulatory requirement that companies disclose percent composition data. This precludes evaluating whether a product is a potentially significant source of exposure to a chemical (e.g., for some products, presence of an ingredient at less than 0.1% of a formulation is unlikely to pose a risk, while presence of that ingredient at 10% of a formulation could be a significant source of human exposure). The absence of percent composition data also complicates the evaluation of whether a product is in compliance with applicable regulatory restrictions. Both regulatory agencies and trade associations manage the potential hazard risks of products by defining thresholds below which an ingredient is deemed safe as used (e.g., use of an ingredient is acceptable provided that it does not exceed 5% of a product's formulation). Unless a product label discloses the percent composition data required to evaluate compliance, GoodGuide caps a product's potential rating at 6 for personal care and cosmetic products and a 7 for household products. The rating can further be reduced if the product contains ingredients that have been restricted or prohibited by regulatory agencies or trade associations.

Adjusting Scores if Ingredients are Granted a “Benchmark Exception”

A Benchmark Exception may be granted for a product when the manufacturer discloses percent composition data to GoodGuide, and that percent composition complies with contextual ingredient restrictions. This is a voluntary disclosure that some manufacturers make it is noted on the product page as “Manufacturer Disclosed. GoodGuide Rated”. GoodGuide increases a product's rating if information indicates that an ingredient does not pose an intrinsic hazard or regulatory concern as it is used in a product. This adjustment has the effect of minimizing the contribution of that ingredient to the product's rating. Such adjustments are indicated in the “Product Ingredient List” section of GoodGuide product pages with a “Benchmark Exception” icon and an explanation of the basis for the ingredient.

Ratings may be adjusted for the following reasons:

Regulatory Benchmark: A government regulatory agency has reviewed the hazardous chemical ingredient and has established an acceptable level of use (i.e. EU cosmetics regulation restricts use methylisothiazoline in rinse off products to a concentration of 0.0015%), and the product complies.

Independent Benchmark: The percent composition data for the product demonstrates that the level of the ingredient is below the most stringent authoritative independent association threshold level that defines safe use and the applicable threshold, is relevant to the hazard and is not the subject of substantial scientific or regulatory critique in regard to its health protectiveness.

Product Certification Benchmark: A government agency or authoritative third-party has reviewed a product against a standard and certified its formulation. In this case, a product must have had its full formulation reviewed and certified by an authoritative third-party¹.

Fragrance Benchmark Exception: For ingredients with a potential sensitization hazard and without other hazards, the ingredient does not exceed a relevant established independent benchmark for the ingredient and the ingredient has been tested in a final formulation in human clinical studies and did not produce a skin sensitization response. GoodGuide reviews the clinical studies provided by the manufacturer before issuing a “fragrance benchmark exception”.

The Role of Expert Judgements

Expert judgments are unavoidable in rating systems, and GoodGuide is no exception. Even the most scientifically grounded assessment requires judgments about the relative importance of various issues and types of evidence, as well as the treatment of data gaps. We acknowledge that users can disagree over the relative weight given to different hazards as there is no objective, correct solution to the problem of how to aggregate such disparate concerns.

See the data section for information about our data quality procedures, update frequency and error correction policies. Note that GoodGuide itself does not test products to generate the data we use in our ratings.



¹ Several criteria were used to select the certifications so recognized:

  1. Certification entity has a scientifically credible methodology for assessing the impacts of ingredients in a formulated product and a published standard that explains its certification criteria.
  2. Certification entity has access to confidential product-level information needed to conduct an assessment (e.g., percent formulation as well as constituents of trade secret or third-party components).

The following third-party certifications are currently recognized as a result of this:

  • EPA Safer Choice
  • Cradle to Cradle
  • UL Ecologo (not a third party)
  • Good Housekeeping Green Seal