Methyl Parathion

CAS ID#: 298-00-0

Affected Organ Systems: Developmental (effects while organs are developing), Hematological (Blood Forming), Neurological (Nervous System)

Cancer Classification:  Please contact NTP, IARC, or EPA with questions on cancer and cancer classification.

Chemical Classification: Organophosphates and carbamates


Methyl parathion is an insecticide that does not occur naturally in the environment. Pure methyl parathion exists as white crystals. Impure methyl parathion is a brownish liquid that smells like rotten eggs.

Methyl parathion is used to kill insects on farm crops, especially cotton. The EPA now restricts how methyl parathion can be used and applied; only trained people are allowed to spray it. Methyl parathion can no longer be used on food crops commonly consumed by children.

Community Members
Community Members

ToxFAQs - Fact sheet that answers the most frequently asked questions about a contaminant and its health effects.

Public Health Statement - Summary about a hazardous substance taken from Chapter One of its respective ATSDR Toxicological Profile.

Toxicological and Health Professionals
Toxicological and Health Professionals

Toxicological Profile - Succinctly characterizes the toxicologic and adverse health effects information for a hazardous substance.

Priority List of Hazardous Substances - Prioritization of substances based on a combination of their frequency, toxicity, and potential for human exposure at National Priorities List (NPL) sites.

Minimal Risk Levels (MRL) - The MRL is an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse, non-cancer health effects over a specified duration of exposure. The information in this MRL serves as a screening tool to help public health professionals decide where to look more closely to evaluate possible risk of adverse health effects from human exposure.

Page last reviewed: February 10, 2021