Paraquat

MedEd Pesticide lists Paraquat as a herbicide in the bipyridylium class.

MedEd Pesticide Summarizes Paraquat at a Glance

Type

Herbicide

Chemical class

Bipyridylium

CAS number

4685-14-7

Formula

C12H14N2+2

Molar mass

186.25 g/mol

EU status

Not approved as an active substance in the EU.

US status

Registered with EPA. 35 active products contain Paraquat.

MedEd Pesticide Summarizes Paraquat’s Toxicity Records

MedEd Pesticide holds 108 toxicity records for Paraquat, from 5 sources. The headline values are below.

Oral LD50 in ratsAcute, swallowed

Lowest reported 100 mg/kg, median 125 mg/kg, from 2 records.

Dermal LD50Acute, skin contact

Lowest reported 236 mg/kg, median 236 mg/kg, from 1 record.

Lowest NOAELLong term, mammals

0.5 mg/kg-day in dog, 90 days. Source: EFSA.

EPA signal wordsActive US products

Danger 34, Warning 1, Caution 0.

See all 108 Paraquat toxicity records in the explorer. The records come from EPA’s Toxicity Values Database, and the methodology explains their limits.

MedEd Pesticide Reports Paraquat’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

0.004 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.

AOELAcceptable operator exposure level

0.0004 mg/kg bw/dayThe level of exposure for people who apply the pesticide at which no adverse effect is expected.

MedEd Pesticide Lists Paraquat’s EU Hazard Classification

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

• H330 Fatal if inhaled
• H301 Toxic if swallowed
• H311 Toxic in contact with skin
• H400 Very toxic to aquatic life
• H410 Very toxic to aquatic life with long-lasting effects
• H319 Causes serious eye irritation
• H372 Causes damage to organs through prolonged or repeated exposure
• H335 May cause respiratory irritation
• H315 Causes skin irritation

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 Paraquat with another pesticide.

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