pirimiphos-methyl (Actellic) Chemical Fact Sheet 6/85
CHEMICAL FACT SHEET FOR:
FACT SHEET NUMBER: 59
DATE ISSUED: JUNE 30, 1985
1. DESCRIPTION OF CHEMICAL
- Generic Name: 0-[2-(diethylamino)-6-methyl-4-pyrimidinyl]0,0-
- Common Name: pirimiphos-methyl
- Trade Name: Actellic
- EPA Shaughnessy Code: 108102
- Chemical Abstracts Service (CAS) Number: 29232-93-7
- Year of Initial Registration: 1984
- Pesticide Type: Insecticide
- Chemical Family: organophosphate
- U.S. and Foreign Producers: ICI Americas, Inc., Imperial Chemical
Industries, PLC., United Kingdom
2. USE PATTERNS AND FORMULATIONS
- Application sites: Stored grain products -- corn, rice, wheat, and
grain sorghum intended for export only.
- Types of formulations: emulsifiable concentrate
- Types and methods of application: sprays
- Application rates: 0.006 to 0.015 lbs. a.i./l,000 lbs. of grain
- Usual carriers: petroleum solvents
3. SCIENCE FINDINGS
- Physical state: liquid
- Color: amber
- Odor: putrid -- a typical organophosphorothioate odor. Odorless when
- Molecular weight: 305
- Melting point: 15-18 degrees C
- Boiling point: Decomposes above 100 degrees C
- Vapor pressure: 1.1 x 10(-4) tor at 30 degrees C
- Flash point: not reported
- Solubility in various solvents: Solubility in water is 5 ppm at
30 degrees C. Miscible in all proportions with methanol, ethanol,
chloroform, acetone, benzene, toluene, and xylene.
- Acute oral LD50: 2050 mg/kg, Toxicity Category III
- Acute dermal LD50: 1505 mg/kg, Toxicity Category II
- Primary dermal irritation: No irritation, Toxicity Category III
- Primary eye irritation: Corneal opacity persisted to 14 days.
Toxicity Category III.
- Skin sensitization: Not a sensitizer.
- Acute inhalation: Uncharacterized. The use pattern precludes
- Neurotoxicity: Not an acute delayed neurotoxic agent at doses up
to 10 mg/kg/day for 90 doses.
- Oncogenicity: Not shown to be an oncogen in rat or mouse studies
at dose levels up to 300 and 500 ppm (highest dose tested),
- Teratogenicity: The Agency has determined that this chemical is not
teratogenic at levels up to 16 mg/kg/day; however, an additional
study in a second species (rats) is still required.
- Reproduction, 3-generation: Two studies adequately demonstrate that
pirimiphos-methyl does not produce reproductive effects. No effects
were demonstrated at dose levels up to 100 ppm.
- Metabolism: The studies suggest that pirimiphos-methyl is rapidly
excreted, and no evidence of bioaccumulation was noted.
- Mutagenicity: This chemical has been determined to be non-mutagenic
in all three required studies.
Physiological and Biochemical Behavioral Characteristics
- Mechanism of pesticidal action: An insecticide which is active by
contact, ingestion, and vapor action, and causes phosphorylation of
the acetylcholinesterase enzyme of tissues, allowing accumulation
of acetylcholine at cholinergic neuro-effector junctions (muscarinic
effects), and at skeletal muscle myoneural junctions and autonomic
ganglia. Poisoning also impairs the central nervous system function.
- Symptoms of poisoning include: Headache, dizziness, extreme
weakness, ataxia, tiny pupils, twitching, tremor, nausea, slow
heartbeat, pulmonary edema, and sweating. Continual absorption at
intermediate dosages may cause influenza-like illness which includes
symptoms like weakness, anorexia, and malaise.
- Metabolism and persistence in plants and animals: The metabolism of
pirimiphos-methyl in plants and animals is not, at this time,
adequately understood in order to establish a tolerance for grain
- Uncharacterized. This use pattern precludes exposure to the
- Avian oral: mallard duck, 76.6 mg/kg
ring-necked pheasant, 17.7 mg/kg.
- Avian dietary: mallard duck, 633 ppm
bobwhite quail, 207 ppm.
- Freshwater fish: coldwater fish (rainbow trout), 0.40 ppm
warmwater fish (bluegill sunfish), 2.9 ppm.
- Acute freshwater invertebrates: Daphnia, 0.21 ppb
- No domestic tolerances exist for this chemical. Tolerances for small
grains have been proposed to support domestic consumption of treated
grains. There is an established tolerance of 5 ppm for imported
Summary Science Statement
- Pirimiphos-methyl is an organophosphorothioate compound with
moderate acute toxicity. This chemical has demonstrated adverse
chronic effects. It is also a moderate toxicant to wildlife
species; however, the registered use precludes exposure to wildlife.
- This chemical is toxic to fish and other wildlife. The proposed
use precludes any impact on endangered species.
- In case of a significant chemical spill, call 1-800-426-9300
5. SUMMARY OF MAJOR DATA GAPS
- A second mammalian species (rat) teratology study.
6. CONTACT PERSON AT EPA
Jay S. Ellenberger
Product Manager (12)
Registration Division (TS-767C)
Office of Pesticide Programs
Environmental Protection Agency
401 M Street S.W.
Washington, DC 20460
Office location and telephone number:
Room 202 Crystal Mall #2
1921 Jefferson Davis Highway
Arlington, VA 22202
DISCLAIMER: THE INFORMATION PRESENTED IN THIS CHEMICAL INFORMATION FACT
SHEET IS FOR INFORMATIONAL PURPOSES ONLY AND NOT TO BE USED TO FULFILL
DATA REQUIREMENTS FOR PESTICIDE REGISTRATION AND REREGISTRATION.