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INFO / METHODOLOGY / Product and Ingredient Data Sources

Product and Ingredient Data Sources

Below we describe the information sources and the methodology we use to construct EWG’s Guide to Healthy Cleaning’s linked datasets of ingredients, products, brands and companies.

Product Details

The core of EWG’s Guide to Healthy Cleaning is an interactive product database that contains ingredients in more than 2,000 products. EWG obtained detailed information on these products from manufacturers’ websites, online retailers and product packaging. Information was first amassed in the winter of 2011-2012 and is updated regularly. Visits to stores during the summer of 2012 provided additional information on the labels associated with some new product formulations now available to consumers. In most cases the information includes a brand name, product name, directions for use, warnings, ingredients and package/advertising text.

Value-Added Information

EWG staff carefully evaluated every product in EWG’s Guide to Healthy Cleaning to identify the product type, its composition and use instructions (including precautions to protect skin and eyes) and product marketing claims.

Product type

EWG categorized each product into one or more of 70+ product categories (e.g., all-purpose cleaner, oxygen bleach, dish detergent). For ease of navigation, these product categories were organized into nine major groups.

Product use/composition

EWG identified how each product is typically used. Many hazard recommendations associated with chemicals depend on a product’s use and/or composition. For instance, chemicals that are hazardous when inhaled are problematic in products that are sprayed. For each product, EWG recorded:

  • Directions for use, including whether the product is meant to be diluted, left on surfaces, wiped off or rinsed off.
  • Manufacturer’s warnings concerning accidental exposure, such as recommendations to wear gloves or goggles or avoid eye contact.
  • The form of the product: solid, liquid, liquid spray, aerosol, wipe etc.
  • Information indicating potential for toxicity, such as pH and levels of volatile organic compounds (VOCs) released during use. Note, as of March 01, 2021, EWG actively seeks pH values for only corrosive cleaning product categories and forms.

Brand and company information

EWG’s Guide to Healthy Cleaning currently features products sold under 197 brand names manufactured by dozens of companies, including brand and company relationships identified primarily through online research.

Because many consumers care about animal testing, EWG’s Guide to Healthy Cleaning also provides the manufacturer’s position on animal testing as obtained from listings assembled by People for the Ethical Treatment of Animals’ (PETA) and Leaping Bunny. We periodically update our database to reflect these organizations' most current listings.

Ingredients in EWG’s Guide to Healthy Cleaning

EWG’s Guide to Healthy Cleaning currently contains information on more than 1,000 ingredients used in cleaning products, culled from labels, manufacturer websites, worker safety documents and from the scientific and industry literature. We assigned a standardized name to each ingredient, often using the International Nomenclature for Cosmetic Ingredients (INCI) standard, with some exceptions where alternate names are more easily recognized by consumers or widely used by industry. Each ingredient name is associated with a unique ingredient identification number in the database.

Creating electronic ingredient lists from product labels, company websites and worker safety documents

EWG parsed (electronically separated) individual ingredients from the ingredient lists on company websites and on product labels where available. The parsing tools we designed do not yet take into account every variation in labeling and likely will never be able to account for the wide range of errors in spacing and delimiting on ingredient labels. Because of these factors, EWG staff members carefully reviewed parsed ingredient lists and manually corrected ingredients that were not accurately separated, routinely updating the parsing program to improve accuracy prior to a manual review.

Some company websites make freely available worker safety documents called Material Safety Data Sheets (MSDSs) or Safety Data Sheets (SDSs). The Occupational Safety and Health Administration (OSHA) requires companies to provide these sheets to workers who may be exposed to hazardous chemicals on the job. SDSs may contain ingredient information not found elsewhere, including the Chemical Abstract Service (CAS) identification numbers for certain ingredients and a range of their relative percentages in products. When relevant, EWG manually extracted information on products and pH from SDSs. Product names on SDSs often do not correspond perfectly with the names on labels, requiring additional review to match each document with the correct product.

Assigning a unique chemical name and identification number to ingredients

Each ingredient was assigned a unique name and identification number in the ingredient database in a multi-step process that involved resolving chemical synonyms and names that were misspelled or did not follow standard industry naming conventions:

  • When ingredient names on product labels or company entries exactly matched the spelling of one of our core database ingredients or its synonyms, we assigned that ingredient the existing chemical name and identification number from our ingredient database.
  • When ingredient names did not exactly match an existing ingredient name, we determined whether the new name was a misspelling of an ingredient in our core database. We processed the new ingredient with a program that identifies possible name matches, first through a match of Chemical Abstract Service (CAS) identification numbers when available, and then through a custom, chemical-name spell checker. Finally, through a manual review of these tentative matches, we either matched the new ingredient with one already in our database or we determined that it was a new, unique ingredient and assigned it a new ingredient identification number.

Additional data stored with a product’s ingredient list

EWG stored information where available on the function of each ingredient – for instance, whether it is used as a surfactant or a preservative. EWG also recorded information from labels about ingredients that a product does not contain.

Grouping ingredients into chemical or functional classes

Many manufacturers choose to describe the ingredients in their products only by their broad chemical class, such as “alcohol ethoxylate,” or by their functional class, such as “preservative,” rather than identifying specific chemical ingredients. EWG staff constructed “substance groups” that correspond to the major chemical or functional classes found in cleaning supplies. Individual ingredients were assigned to groups based on extensive review of government and industry documents.

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