Formetanate HCL (Carzol) Chemical Fact Sheet 9/83
CHEMICAL FACT SHEET FOR:
FACT SHEET NUMBER: 11
DATE ISSUED: SEPTEMBER, 1983
1. DESCRIPTION OF CHEMICAL
- Generic Name: n,n-dimethyl-n'-[3-[[(methylamino)carbonyl]oxy]phenyl]
- Common Name: formetanate hydrochloride(HC1)
- Trade Name: Carzol
- EPA Shaughnessy Code: 097301
- Chemical Abstracts Service (CAS) Number: 23422-53-9
- Year of Initial Registration: 1969
- Pesticide Type: Acaricide/Insecticide
- Chemical Family: Methylcarbamate hydrochloride
- U.S. and Foreign Producers: Imported into the U.S. from West Germany,
where it is manufactured by Schering A.G. Chemical Company. In the
U.S., the sole importer and distributor of the chemical is Nor-Am
2. USE PATTERNS AND FORMULATIONS
- Application sites: citrus, pome and stone fruits, and alfalfa grown
- Types of formulations: 92% soluble powder
- Types and methods of application: ground and aerial
- Application rates: range from 0.0575 lbs. a.i./A to 1.38 lbs. a.1./A
- Usual carriers: water
3. SCIENCE FINDINGS
- Chemical Characteristics
- Physical state: crystalline solid
- Color: white
- Odor: essentially odorless
- Melting point: 200-202 C
- Toxicological Characteristics
- Acute oral LD50: 26.4 m/kg (rat), Toxicity Category I
- Acute dermal LD50: > 10,000 mg/kg (rabbit), Toxicity Category III
- Primary dermal irritation: no irritation (rabbit), Toxicity
- Primary eye irritation: One-fifth of the animals (rabbit) showed
irritation at,a 7-day observation period. The effect was considered
to be presumptively not reversible in 21 days.
- Acute inhalation LC50: 0.29 mg/liter (rat), Toxicity Category II
- The chronic studies are data gaps. The original studies were
conducted by IBT, and have been determined to be invalid. No
replacement studies have been submitted. A commitment has been made
by Nor-Am Chemical Company to replace the IBT studies.
- A risk assessment cannot be completed at this time due to gaps in
the data base.
- Physiological and Biochemical Behavioral Characteristics
- Mechanism of pesticidal action: A contact Insecticide which causes
reversible carbamylation of the acetylcholinesterase enzyme.
Poisoning also impairs the central nervous system function.
- Metabolism and persistence in plants and animals: In plants,
formetanate HC1 is absorbed into the leaves, but is not translocated
to untreated areas. On the fruit, weathering and growth dilution
appear to be the primary cause of the dissipation of formetanate
HC1. In animals, formetanate is eliminated in the urine and feces.
The major metabolic pathway involves hydrolysis to metabolites and
subsequent formation of the glucuronide and ethereal sulfate
conjugates of m-acetamidophenol.
- Environmental Characteristics
Available data are insufficient to fully assess the environmental fate
of formetanate HC1. It appears to rapidly degrade in soil under
aerobic conditions. This chemical appears to leach in soil and
therefore has a potential for groundwater contamination. A 24-hour
reentry interval has been established for this chemical on orchard
- Ecological Characteristics
- Avian oral LD50 - Mallard duck, 11.7 mg/kg; Bobwhite quail, 43.1
- The avian dietary LC50 studies, freshwater fish LC50 studies, and
acute LC50 freshwater invertebrate studies Pre data gaps.
- Formetanate HC1 is characterized as highly toxic to birds. It is
slightly toxic to warmwater fish, and moderately toxic to estuarine
and marine organisms. It is moderately toxic to honeybees with
direct contact spray, but it has very low toxicity to bees when they
are exposed to residues on plants.
- Tolerance Assessment
- A full tolerance reassessment cannot be completed because of certain
residue chemistry and toxicology data gaps. The current values for
the acceptable daily intake (ADI) of 0.025 mg/kg/day and the maximum
permissible intake (MPI) of 1.5 mg/kg/day are provisional. This is
because a number of multiple dose toxicity studies submitted to
establish the ADI/MPI were conducted by IBT and have been determined
to be invalid. Another reassessment and recalculation will be made
when the studies required to fill the toxicology data gaps are
submitted and reviewed.
- A petition for tolerance for residues in or on alfalfa forage and
alfalfa hay must be submitted to support the alfalfa grown-for-seed
use. No residue data are available. A petition for a food additive
tolerance for apple pomace must be submitted.
Commodity Parts Per Million
Plums (fresh prunes) 2
- Summary Science Statement
- Formetanate HC1 is highly toxic from an oral route of exposure. It
demonstrates low toxicity from the dermal route of exposure and
moderate toxicity from the inhalation route of exposure. It is
considered to be an eye irritant. The chronic studies are data
- Formetanate HC1 appears to leach in soil and therefore has a
potential for contamination of groundwater. However, available data
are insufficient to fully assess the environmental fate of this
chemical. A 24-hour reentry interval has been established.
- This chemical is highly toxic to birds. It is slightly toxic to
fish, and moderately toxic to estuarine and marine organisms.
- A tolerance reassessment cannot be made until the studies required
to fill the toxicology data gaps have been submitted and validated.
A petition for a tolerance for residues in or on alfalfa hay and
alfalfa forage must be submitted. A food additive petition must be
submitted for apple pomace.
4. SUMMARY OF REGULATORY POSITION AND RATIONALE
- The Agency has determined that it should continue to allow the
registration of formetanate HC1. Adequate studies are available to
assess the acute toxicological effects of formetanate HC1 to humans.
None of the criteria for unreasonable adverse effects listed in 40 CFR
162.11(a) have been met or exceeded. However, because of gaps in the
data base, a full risk assessment of formetanate HC1 cannot be made at
- A full tolerance reassessment cannot be completed because of residue
chemistry and toxicology data gaps.
- Available data are insufficient to fully assess the environmental fate
of carbaryl. A 24-hour reentry interval has been established for
formetanate HC1. This chemical appears to have the potential to
5. SUMMARY OF MAJOR DATA GAPS
- Residue data on alfalfa
- Chronic feeding studies - 2 species
- Oncogenicity studies - 2 species
- Teratogenicity studies - 2 species
- Reproduction studies - 2 species
- Hydrolysis study
- Mobility studies
- Photodegradation studies
- Dissipation studies
- Avian dietary LC50 studies
- Aquatic organism testing
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
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.