Banned Pesticides: Which Ones Were Banned and Why

A banned pesticide is one whose production and use a law, agency order or treaty has withdrawn. International treaties ban Aldrin, Chlordane, Chlordecone, Dieldrin, Endrin, Heptachlor and DDT. The United States Environmental Protection Agency banned DDT because its massive use posed unacceptable risks. DDT is a persistent organic pollutant, yet it is still used outside the United States. EPA reviews each registered pesticide at least every 15 years for unreasonable adverse effects to human health. EPA also removed DCPA, sold as Dacthal, because it could change fetal thyroid hormone levels. EPA revoked carbofuran food tolerances because this carbamate harms health in humans, animals, wildlife and fish. DCPA was still sold in the United States before 2024.

What Is a Banned Pesticide?

A banned pesticide is a pesticide whose production and use a law, an agency order or a treaty has withdrawn. The Stockholm Convention bans or restricts persistent organic pollutants such as DDT through a global treaty negotiated under UNEP. A ban removes the product, while a restriction only limits where and how it is used. Under the treaty, parties must take measures to eliminate the production and use of the chemicals listed under Annex A. In the United States, the Environmental Protection Agency withdraws a pesticide by cancelling its registration. General use of DDT stopped being legal there on 31 December 1972 after the EPA cancellation. Some uses stay legal after a ban, because treaty and agency actions list exempted uses.

Which Pesticides Are Banned Under International Treaties?

The pesticides banned under international treaties are Aldrin, Chlordane, Chlordecone, Dieldrin, Endrin, Heptachlor and DDT. Stockholm Convention Annex A lists Aldrin, Chlordane, Chlordecone, Dieldrin, Endrin and Heptachlor for elimination. DDT sits under Annex B, which restricts it, with an acceptable purpose for disease vector control. The two annexes differ in obligation. Parties must restrict the production and use of Annex B chemicals. Applicable acceptable purposes and specific exemptions in the Annex still apply.

Why Was DDT Banned in the United States?

The United States Environmental Protection Agency banned DDT because its continued massive use posed unacceptable risks to the environment. The EPA administrator judged that DDT posed potential harm to human health. DDT persists in the environment and accumulates in fatty tissues, so each application added to a lasting burden. DDE, a DDT breakdown product, has been associated with reproductive failure of several avian species. The main route is eggshell thinning. The publication of Rachel Carson’s Silent Spring in 1962 stimulated widespread public concern over the dangers of improper pesticide use. Use had already declined. Insect resistance, more effective alternatives and growing public concern over adverse environmental side effects drove the decline. A 2016 study by Miguel A Mora in Environmental toxicology and chemistry found significant decreases. All DDE residues observed in birds fell in North America. In central North America, p,p’-DDE in bird eggs fell from 2.5 to 1.64 μg/g wet weight. The period ran from 1980 to the mid-2000s. In western North America, it fell from 29.5 to 1.01 μg/g wet weight over the same period.

How Much DDT Was Applied Before the Ban?

The DDT applied before the ban peaked at nearly 80 million pounds in 1959, so much use came early. Paul Hermann Müller had discovered DDT’s insecticidal action in 1939. DDT usage then declined steadily to about 13 million pounds in 1971, most of it applied to cotton. Over the 30 years before the ban, approximately 675,000 tons of DDT were applied domestically. The usage records report these totals in pounds and tons. The fall from 1959 to 1971 matches the decline driven by resistance, alternatives and public concern.

Did the DDT Ban Take Effect Immediately?

No. The United States Environmental Protection Agency delayed the effective date of its DDT cancellation until the end of 1972. The DDT ban did not take effect immediately. On June 14, 1972, the EPA administrator issued an order finally cancelling nearly all remaining Federal registrations of DDT products. The delay permitted an orderly transition to substitute pesticides. Public health, quarantine and a few minor crop uses were excepted, as was export of the material.

Is DDT Still Used Today?

Yes. DDT is a persistent organic pollutant, yet DDT is still used today outside the United States. The World Health Organization recommends it as one of 12 pesticides for indoor residual spray programs. The Stockholm Convention allows a limited exemption for DDT use against mosquitoes that transmit the microbe causing malaria. DDT remains in use outside the United States for the control of mosquitoes that spread malaria. It is up to individual countries to decide whether to use DDT. Parties must take measures to restrict the production and use of Annex B chemicals under acceptable purposes.

Is DDT Harmful to Human Health?

Yes. Under Registration Review, EPA reviews each registered pesticide at least every 15 years for unreasonable adverse effects to human health. DDT is harmful to human health, because the EPA suspects reproductive effects in humans. That suspicion rests on studies in animals. DDT will accumulate in fatty tissues, which is where the body holds it. In vitro and animal studies indicating that DDT has estrogenic properties form the basis for studying breast cancer risk. A 2013 study by Susan Z Ingber in Regulatory toxicology and pharmacology found no support. The hypothesis was that DDT/DDE exposure increases the risk of breast cancer in humans. Human effects beyond the suspected reproductive ones therefore remain unproven.

Can DDT Cause Cancer?

Yes. DDT is a persistent organic pollutant that U.S. and international authorities classify as a probable human carcinogen. DDT can cause cancer, as that classification shows. In 2015 the International Agency for Research on Cancer placed DDT in Group 2A, probably carcinogenic to humans. Some animals exposed to DDT in studies developed liver tumors. A 2025 study by Rodrigo Ugalde-Resano in Reviews on environmental health reported a positive association. It linked p,p’-DDT biological concentrations to breast cancer. That association came from prospective nested case control studies with more than 10 years of follow-up. Breast cancer was positively related to p,p’-DDE biological concentrations in the same work. These findings conflict with the 2013 review of human breast cancer data, so the evidence stays mixed.

Why Did EPA Remove DCPA (Dacthal) From the Market?

EPA removed DCPA, sold as Dacthal, from the market because DCPA could change fetal thyroid hormone levels in unborn babies. DCPA poses significant health risks for farmworkers, especially pregnant women and their fetuses. Changes to fetal thyroid hormone levels are generally linked to low birth weight and impaired brain development. They are linked to decreased IQ and impaired motor skills. EPA relied on the best available science, which included robust studies demonstrating thyroid toxicity. In 2013, EPA required the sole manufacturer to submit more than 20 studies supporting the existing DCPA registrations. In April 2022, EPA issued a very rarely used Notice of Intent to Suspend the DCPA technical-grade product. On Oct. 22, 2024, the U.S. Environmental Protection Agency announced the cancellation of all products containing DCPA, the pesticide dimethyl tetrachloroterephthalate.

Why Did EPA Revoke Carbofuran Food Tolerances?

EPA revoked carbofuran food tolerances because carbofuran, an anticholinesterase carbamate, harms health in humans, animals, wildlife and fish. A 1994 study by R C Gupta in the Journal of toxicology and environmental health reached a firm conclusion. Adverse health effects are inevitable in humans, animals, wildlife, and fish. Carbofuran is commonly used as an insecticide, nematicide and acaricide in agricultural practice throughout the world. On May 11, 2009, the EPA announced it was formally revoking all food tolerances for carbofuran, effective December 31, 2009. After 2009, the FDA has authority to condemn and order destruction of any food commodity found to contain carbofuran residue. There is no recall program for unused Furadan after 2009.

Was DCPA Still Sold in the United States Before 2024?

Yes. DCPA was still sold in the United States before 2024. EPA announced the cancellation of all DCPA products only on October 22, 2024. DCPA, or Dacthal, is the pesticide dimethyl tetrachloroterephthalate. In 2013, the agency issued a Data Call-In to AMVAC Chemical Corporation, the sole manufacturer of DCPA. The call-in required more than 20 studies to support the then-existing registrations of DCPA. After EPA’s emergency suspension, AMVAC sent a letter. It stated an intent to voluntarily cancel the remaining DCPA products in the U.S. The cancellation then ended the remaining registrations under FIFRA.