The EWG, or Environmental Working Group, is a nonprofit advocacy organization focused on environmental and public health. Founded by Ken Cook and based in Washington, D.C., it operates under the tagline “Know your environment. Protect your health.” The organization is best known for its consumer-facing databases and guides that rate everything from produce pesticide levels to cosmetic ingredient safety. With annual revenue of about $21.7 million, nearly all of it from contributions and grants, the EWG has become one of the most widely referenced sources for consumers trying to navigate chemical exposures in food, water, and personal care products.
What the EWG Actually Does
The EWG sits at the intersection of environmental research and consumer advocacy. Rather than conducting original laboratory studies, it takes publicly available government data and repackages it into tools designed for everyday shoppers. Its analysts pull from sources like the USDA’s Pesticide Data Program, EPA toxicity reviews, and utility-reported water quality data, then apply their own scoring systems to flag potential health concerns.
The organization also lobbies for stricter chemical regulations and publishes investigative reports on topics ranging from farm subsidies to industrial pollution. Its current priority issues include PFAS (commonly called “forever chemicals”), formaldehyde, heavy metals, phthalates, flame retardants, lead, and microplastics. In recent years, it has pushed back against federal legislation it says would weaken state-level protections from harmful chemicals.
The Dirty Dozen and Clean Fifteen
The EWG’s most famous product is its annual Shopper’s Guide to Pesticides in Produce, which ranks fruits and vegetables into two lists: the Dirty Dozen (highest pesticide residues) and the Clean Fifteen (lowest). These lists go viral every spring and have a noticeable influence on grocery shopping habits.
The methodology behind the lists draws on USDA testing of tens of thousands of produce samples. In 2025, the EWG refined its approach to evaluate four metrics, with “abundance” (the percentage of samples with at least one pesticide detected) being one key factor. Each type of produce receives a score out of 400 based on those four measures. What sets the EWG’s analysis apart from simply reporting USDA data is the addition of toxicity weighting. The organization compares the concentration of each pesticide found to its “no observed adverse effect level,” the highest dose that caused no harm in animal studies. Produce with pesticides detected at concentrations closer to those thresholds scores worse.
Critics, including some toxicologists, argue that nearly all residues found by the USDA fall well below levels considered harmful and that the Dirty Dozen list can discourage people from eating fruits and vegetables. The EWG counters that federal safety thresholds are outdated and don’t account for cumulative exposures from multiple chemicals.
Skin Deep Cosmetics Database
The Skin Deep database rates personal care products on a hazard scale of 1 to 10. A product’s score isn’t simply an average of its ingredient scores. Instead, it uses a weight-of-evidence approach that factors in all known and suspected hazards linked to the ingredients.
The database evaluates ingredients across more than a dozen concern categories: cancer links, reproductive toxicity, allergies and immune system effects, hormone disruption, neurotoxicity, organ system toxicity, environmental persistence, and more. It also flags ingredients restricted or prohibited in cosmetics by the U.S., EU, Japan, or Canada, and notes when ingredients may penetrate skin more readily due to small particle size or application on sensitive areas like lips or damaged skin.
For consumers, the practical appeal is straightforward. You can search a sunscreen, shampoo, or lipstick by name and see a color-coded score before you buy. The database has pushed some brands to reformulate products and has fueled broader demand for ingredient transparency in the beauty industry.
Tap Water Database
The EWG’s Tap Water Database lets you enter your zip code and see what contaminants have been detected in your local water supply, along with the levels found. The twist is that the EWG publishes its own health-based guidelines, which are dramatically stricter than federal legal limits set by the EPA.
The gaps between the two standards are striking. For atrazine, a common herbicide, the federal limit is 3 parts per billion while the EWG recommends 0.1 ppb. For nitrate, the federal limit is 10 parts per million compared to the EWG’s guideline of 0.14 ppm. For trihalomethanes, byproducts of water disinfection, the legal limit is 80 ppb versus the EWG’s 0.15 ppb. The organization argues that federal limits are shaped by political compromise and cleanup costs rather than health science alone.
This approach is one reason the EWG generates controversy. Water utilities and some public health officials point out that meeting legal standards means water is safe to drink, and that the EWG’s guidelines can cause unnecessary alarm. The EWG responds that legal limits haven’t been updated in decades for many contaminants and fail to reflect newer research on low-dose, long-term exposure.
EWG Verified Certification
Beyond its free databases, the EWG runs a product certification program. Products carrying the EWG Verified seal must meet several requirements: full disclosure of all ingredients on the label (including specific fragrance components, which many brands typically hide behind the generic term “fragrance”), adherence to good manufacturing practices, and a commitment to report any adverse events to both the FDA and the EWG. The organization also reserves the right to randomly test verified products to confirm they meet its standards.
The seal appears on personal care products, cleaning supplies, and baby products. For manufacturers, earning the mark is a marketing advantage with health-conscious consumers. For shoppers, it signals that a product has passed a third-party review beyond what federal regulation requires.
Funding and Leadership
The EWG reported total revenue of $21.7 million in its most recent tax filing, with $19.6 million coming from contributions and grants. Ken Cook remains president and has led the organization for more than 30 years. The board of directors includes a mix of physicians, entrepreneurs, and public figures, among them actress Michelle Pfeiffer, pediatrician Dr. Harvey Karp, and physician Dr. Mark Hyman.
The organization is classified as a 501(c)(3) nonprofit, meaning donations are tax-deductible. It does not accept funding from the companies whose products it rates, a firewall that supports its claim of independence. Revenue comes primarily from individual donors and philanthropic foundations, though the exact split between the two isn’t publicly detailed in its tax filings.
Common Criticisms
The EWG occupies an unusual space: widely trusted by consumers but frequently questioned by scientists and industry groups. The most common criticism is that its scoring systems emphasize hazard (whether a substance could cause harm under any conditions) over risk (whether the amount you’re actually exposed to is dangerous). A chemical that causes cancer at extremely high doses in lab animals may receive a high hazard score even if the trace amounts found in a product pose negligible real-world risk.
Some food scientists have argued that the Dirty Dozen list, in particular, does more harm than good if it leads lower-income shoppers to avoid conventional produce rather than eating more fruits and vegetables overall. The EWG maintains that its lists are meant to guide choices, not discourage produce consumption, and that its work fills a gap left by regulatory agencies that move slowly to update safety standards.
Regardless of where you fall on these debates, the EWG has undeniably shifted public expectations around ingredient transparency and chemical safety. Its databases remain some of the most-visited consumer health tools online, and its advocacy has contributed to state and federal action on PFAS contamination, pesticide regulation, and cosmetic ingredient disclosure.