Pesticide Label Warning Search

Methodology

The Center identified all end-use pesticide products that had an active Section 3 registration from the EPA's Active Pesticide Product Registration Informational Listing (APPRIL) database. PDFs of every available label of those active registrations (about 93,267) were downloaded from the EPA's Pesticide Product Label System (PPLS) on 2/3/2026. Each document then underwent Optical Character Recognition (OCR) and text extraction.

For this analysis, the resulting text was evaluated using a biomedical Natural Language Processing (NLP) workflow combined with keyword-based detection for three predefined terms: cancer, carcinogen, and carcinogenicity. Labels identified as having those three words in the context of a health warning were then captured in a spreadsheet.

There were 1,259 labels identified with the word “California” in close proximity to the health warning (identified as having a Prop 65 warning) and removed from further analysis. The remaining labels were manually reviewed and labels with mistaken OCR text and keywords in a non-relevant context were removed. Unexpectedly, 75 labels were found to specifically state that glyphosate does not cause cancer, which were also removed from our analysis because this does not constitute a warning.

The remaining 482 labels had a federally-mandated cancer warning on the label. Upon further inspection, 171 of those labels had warnings required by the Occupational Safety and Health Administration (OSHA), and not EPA. These warnings were for pesticides like creosote (coal tar), ethylene oxide and formaldehyde, that OSHA has linked to human cancer. That left 311 pesticide labels containing six ingredients (dichlorvos, oxadiazon, paraformaldehyde, 1,3-D, triphenyltin hydroxide and chromic acid) that contained a cancer warning required by the EPA’s pesticide office.

To identify currently-registered pesticides that the EPA has found some link to pesticides, we extracted information from a 2024 EPA memo that identified the cancer classification status of all past and presently-registered pesticides in the US. All “probable” or “likely” carcinogens and all “possible” or “suggestive” carcinogens were identified and compiled. All ingredients that were not currently registered in the US were removed from further analysis. This left 38 currently-registered pesticide ingredients that the EPA has designated a “probable” or “likely” human carcinogen and 87 currently-registered pesticide ingredients that the EPA has designated as having “possible” or “suggestive” evidence of human carcinogenic potential. All five ingredients that EPA has required a cancer warning for are present on these lists.