Parathion

MedEd Pesticide lists Parathion as an insecticide in the organophosphate class.

MedEd Pesticide Summarizes Parathion at a Glance

Type

Insecticide

Chemical class

Organophosphate

CAS number

56-38-2

Formula

C10H14NO5PS

Molar mass

291.26 g/mol

EU status

Not approved as an active substance in the EU.

US status

Not registered with EPA. All 1502 products that contained Parathion are cancelled.

MedEd Pesticide Summarizes Parathion’s Toxicity Records

MedEd Pesticide holds 73 toxicity records for Parathion, from 8 sources. The headline values are below.

Oral LD50 in ratsAcute, swallowed

Lowest reported 2 mg/kg, median 7.5 mg/kg, from 2 records.

Dermal LD50Acute, skin contact

Lowest reported 6.8 mg/kg, median 10.9 mg/kg, from 2 records.

Lowest NOAELLong term, mammals

0.0024 mg/kg-day in dog, 6 months. Source: ToxRefDB.

See all 73 Parathion toxicity records in the explorer. The records come from EPA’s Toxicity Values Database, and the methodology explains their limits.

MedEd Pesticide Reports Parathion’s EU Safety Reference Values

MedEd Pesticide takes these values from the EU, which sets them when it assesses an active substance. They are expressed per kilogram of body weight.

ADIAcceptable daily intake

0.0006 mg/kg bw/dayThe amount a person can take in every day over a lifetime without appreciable health risk.

ARfDAcute reference dose

0.005 mg/kg bwThe amount that can be taken in over a short period, such as one meal or one day, without appreciable health risk.

MedEd Pesticide Lists Parathion’s EU Hazard Classification

MedEd Pesticide lists the harmonised EU hazard statements for Parathion below.

• H300 Fatal if swallowed
• H330 Fatal if inhaled
• H311 Toxic in contact with skin
• H400 Very toxic to aquatic life
• H410 Very toxic to aquatic life with long-lasting effects
• H372 Causes damage to organs through prolonged or repeated exposure

MedEd Pesticide takes EU status, reference values and hazard classification from the EU Pesticides Database. MedEd Pesticide takes US status from EPA’s Pesticide Product Information System (dated 2026-10-13) and chemical identity from PubChem. Retrieved 2026-10-16. Values and approvals change, so check the source for the current entry. See the methodology and the glossary, or compare Parathion with another pesticide.

MedEd Pesticide. (2026). Parathion. https://mededpesticide.org/pesticides/parathion/ (accessed Month Day, Year)