Endrin
Endrin·Affects brain, liver
A highly toxic organochlorine insecticide banned in the United States in 1986. Persistent in soil and sediment, still detected at low levels in groundwater near former use areas.
Endrin
EPA limit
0.002 mg/L (MCL)
Most at risk
Rural well-water households in former cotton and grain growing regions
Found in
City water · Well water
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
Endrin is one of the most acutely toxic organochlorine insecticides ever used. It targets the central nervous system, and even modest acute exposures cause headaches, dizziness, nausea, convulsions, and in severe cases death. Several mass poisoning incidents from contaminated flour and water occurred internationally in the 1960s and 1970s.
Chronic exposure damages the liver and the central nervous system. The compound bioaccumulates in fatty tissue and the brain. The EPA classifies endrin as not classifiable as to human carcinogenicity due to limited data, but the acute and chronic neurotoxicity alone justify the very low drinking water limit.
Unlike most organochlorines, endrin does not concentrate in body fat as efficiently and is metabolized more rapidly, but the compound is so acutely toxic that the EPA set the MCL at the same level as chlordane (2 ppb) based on neurological endpoints.
Where it comes from
How it gets into your water
Endrin was applied to cotton, grains, sugarcane, and tobacco from the 1950s until the EPA cancelled all uses in 1986. It binds tightly to soil and degrades very slowly, with a half-life measured in years to decades depending on conditions.
Legacy contamination in fields, sediment, and aquifers continues to produce occasional low-level detections. Erosion of treated soil into rivers and lakes is a continuing input, particularly after heavy rainfall events that disturb stream and reservoir sediment.
No new applications are permitted in the United States, so all current contamination is legacy.
Legacy cotton and grain fields
Pre-1986 applications still in soil
Shallow groundwater
Migrates from contaminated sediment
Sediment-laden surface water
Re-suspension during storm events
Find out for yourself
Is it in your water?
Public utilities test for endrin and report results in their annual Consumer Confidence Report. Detections in city water are now rare.
Private well owners in regions with historical cotton, sugarcane, or grain production should consider testing for endrin as part of a broader organochlorine panel. These compounds (endrin, chlordane, heptachlor, lindane, toxaphene) tend to occur together because they were applied for similar purposes in the same regions.
The fix
How AquaOx filters it
Endrin is filtered efficiently by activated carbon. The coconut shell carbon stage in The AquaOx adsorbs endrin molecules as water passes through, with independent testing showing reductions above 95%.
For well-water households in regions with historical use, we recommend pairing The AquaOx with our FE Edition or RE Edition if iron or hydrogen sulfide is also present, and adding the under-sink RO for additional drinking-water polish.