chemical information


Chemical Class:

Organophosphate Pesticides and Metabolites

Found in these people:

Lucy Waletsky, Charlotte Brody, Lexi Rome, Andrea Martin, Monique Harden, Davis Baltz

Found in these locations:

Pleasantville, NY; Round Hill, VA; Mill Valley, CA; Sausalito, CA; New Orleans, LA; Berkeley, CA


Organophosphate (OP) pesticides like chlorpyrifos cause significant neurotoxicity in laboratory animals and humans, which is not surprising since they were designed to attack the nervous system of insects. Although these pesticides are not as persistent as some environmental chemicals, they are generally more toxic to the young compared to adults. This means that even short-term exposures, such as during pregnancy or childhood, can result in toxicity. Chlorpyrifos metabolite (3,5,6-TCP) is a common metabolite of chlorpyrifos.

In humans, chlorpyrifos can cause gastrointestinal effects (nausea, diarrhea, vomiting and cramping). Neurological effects, which are likely the result of excessive cholinergic activity, include headaches, blurred vision, numbness, memory impairment, altered nerve conduction and dizziness. Other signs of chlorpyrifos poisoning include muscle cramps, muscle twitching, increased heart rate, salivation, skin flushing, tearing, sweating, respiratory distress, pulmonary edema, and increased urination (ATSDR 1998b).

Effects of chlorpyrifos in laboratory animals include: neurotoxicity (decreased movement, tremors, excess salivation); respiratory toxicity (gasping, pneumonia); cardiovascular toxicity (pericarditis); adrenal toxicity (cellular effects) and decreased body temperature. Developmental effects include neurotoxicity and delayed skeletal development (ATSDR 1998b).

Chlorpyrifos metabolite (3,5,6-TCP)

Organophosphate pesticides were previously marketed for home use and are now used on produce. Known neurotoxins that are particularly toxic to developing fetuses, infants and children

Chlorpyrifos metabolite (3,5,6-TCP) has been found in 6 of the 9 people tested in EWG/Commonweal studies.

Results for Chlorpyrifos metabolite (3,5,6-TCP)

in urine

Showing results from EWG/Commonweal Study #1, industrial chemicals and pesticides in adults

EWG/Commonweal results

  • geometric mean: 3.47 ppb in urine
  • found in 6 of 9 people in the group
ppb in urine 24.1

Chlorpyrifos metabolite (3,5,6-TCP) results