The majority of ionic perchlorates are commercially produced salts commonly used as oxidizers for pyrotechnic devices and for their ability to control static electricity in food packaging.

[15][16] The metastable character of perchlorate in the presence of reducing cations such as Fe2+ in solution is due to the difficulty to form an activated complex facilitating the electron transfer and the exchange of oxo groups in the opposite direction.

Although thermodynamically a mild reductant, Fe2+ ion exhibits a stronger trend to remain coordinated by water molecules to form the corresponding hexa-aquo complex in solution.

The high activation energy of the cation binding with perchlorate to form a transient inner sphere complex more favourable to electron transfer considerably hinders the redox reaction.

[17] The redox reaction rate is limited by the formation of a favorable activated complex involving an oxo-bridge between the perchlorate anion and the metallic cation.

[18] It depends on the molecular orbital rearrangement (HOMO and LUMO orbitals) necessary for a fast oxygen atom transfer (OAT)[19] and the associated electron transfer as studied experimentally by Henry Taube (1983 Nobel Prize in Chemistry)[20][21] and theoretically by Rudolph A. Marcus (1992 Nobel Prize in Chemistry),[22] both awarded for their respective works on the mechanisms of electron-transfer reactions with metal complexes and in chemical systems.

Results from surveys of ground water, ice, and relatively unperturbed deserts have been used to estimate a 100,000 to 3,000,000 tonnes (110,000 to 3,310,000 tons) "global inventory" of natural perchlorate presently on Earth.

[47][48][49][50][51] Perchlorates are of concern because of uncertainties about toxicity and health effects at low levels in drinking water, impact on ecosystems, and indirect exposure pathways for humans due to accumulation in vegetables.

[53] Removal and recovery methods of these compounds from explosives and rocket propellants include high-pressure water washout, which generates aqueous ammonium perchlorate.

By late 2003, the State of California and the Santa Clara Valley Water District had confirmed a groundwater plume currently extending over nine miles through residential and agricultural communities.

Large ion exchange treatment units are operating in three public water supply systems which include seven municipal wells with perchlorate detection.

The potentially responsible parties, Olin Corporation and Standard Fuse Incorporated, have been supplying bottled water to nearly 800 households with private wells,[when?]

The perchlorate released from historic use of Chilean nitrate based fertilizer which the U.S.imported by the hundreds of tons in the early 19th century can still be found in some groundwater sources of the United States, for example Long Island, New York.

[62] Recent improvements in analytical sensitivity using ion chromatography based techniques have revealed a more widespread presence of natural perchlorate, particularly in subsoils of Southwest USA,[63] salt evaporites in California and Nevada,[64] Pleistocene groundwater in New Mexico,[65] and even present in extremely remote places such as Antarctica.

[66] The data from these studies and others indicate that natural perchlorate is globally deposited on Earth with the subsequent accumulation and transport governed by the local hydrologic conditions.

Laboratory experiments in conjunction with isotopic studies[67] have implied that perchlorate may be produced on earth by oxidation of chlorine species through pathways involving ozone or its photochemical products.

[75] The direct ecological effect of perchlorate is not well known; its impact can be influenced by factors including rainfall and irrigation, dilution, natural attenuation, soil adsorption, and bioavailability.

Ex situ treatments include ion exchange using perchlorate-selective or nitrite-specific resins, bioremediation using packed-bed or fluidized-bed bioreactors, and membrane technologies via electrodialysis and reverse osmosis.

[78] Ion exchange technology has advantages of being well-suitable for perchlorate treatment and high volume throughput but has a downside that it does not treat chlorinated solvents.

[77] In situ bioremediation has advantages of minimal above-ground infrastructure and its ability to treat chlorinated solvents, perchlorate, nitrate, and RDX simultaneously.

[81] At very high doses (70,000–300,000 ppb) the administration of potassium perchlorate was considered the standard of care in the United States, and remains the approved pharmacologic intervention for many countries.

[82] In 2010, the EPA's Office of the Inspector General determined that the agency's own perchlorate reference dose (RfD) of 24.5 parts per billion protects against all human biological effects from exposure, as the federal government is responsible for all US military base groundwater contamination.

[88][needs update] In 2006, a study reported a statistical association between environmental levels of perchlorate and changes in thyroid hormones of women with low iodine.

[90] Soon after the revised Blount Study was released, Robert Utiger, a doctor with the Harvard Institute of Medicine, testified before the US Congress and stated: "I continue to believe that that reference dose, 0.007 milligrams per kilo (24.5 ppb), which includes a factor of 10 to protect those who might be more vulnerable, is quite adequate.

"[91] In 2014, a study was published, showing that environmental exposure to perchlorate in pregnant women with hypothyroidism is associated with a significant risk of low IQ in their children.

[93] In the early 1960s, potassium perchlorate used to treat Graves' disease was implicated in the development of aplastic anemia—a condition where the bone marrow fails to produce new blood cells in sufficient quantity—in thirteen patients, seven of whom died.

[96][4] In 2002, the EPA completed its draft toxicological review of perchlorate and proposed an reference dose of 0.00003 milligrams per kilogram per day (mg/kg/day) based primarily on studies that identified neurodevelopmental deficits in rat pups.

[97] In 2003, a federal district court in California found that the Comprehensive Environmental Response, Compensation and Liability Act applied, because perchlorate is ignitable, and therefore was a "characteristic" hazardous waste.

One of the key differences results from how the point of departure is viewed (i.e., NOEL or "lowest-observed-adverse-effect level", LOAEL), or whether a benchmark dose should be used to derive the RfD.

[111] Following the NRDC lawsuit, in 2023 the US Court of Appeals for the DC Circuit ordered EPA to develop a perchlorate standard for public water systems.