PMEP Home Page --> Pesticide Active Ingredient Information --> Insecticides and Miticides --> Fenitrothion (Sumithion) to Methyl Parathion --> Formetanate HCL (Carzol) --> Formetanate HCL (Carzol) Chemical Fact Sheet 9/83

Formetanate HCL (Carzol) Chemical Fact Sheet 9/83

                          CHEMICAL FACT SHEET FOR:
                               FORMETANATE HCL

FACT SHEET NUMBER: 11

DATE ISSUED: SEPTEMBER, 1983

                       1.  DESCRIPTION OF CHEMICAL

- Generic Name:  n,n-dimethyl-n'-[3-[[(methylamino)carbonyl]oxy]phenyl]
  methanimidamide monohydrochloride
- 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
  Chemical Company.

                    2.  USE PATTERNS AND FORMULATIONS

- Application sites:  citrus, pome and stone fruits, and alfalfa grown
  for seed.
- 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
    Category IV
  - 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
  crops.

- Ecological Characteristics

  - Avian oral LD50 - Mallard duck, 11.7 mg/kg; Bobwhite quail, 43.1
    mg/kg
  - 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.

    Tolerances:

           Commodity                               Parts Per Million

           Peaches                                        5
           Grapefruit                                     4
           Lemons                                         4
           Limes                                          4
           Nectarines                                     4
           Oranges                                        4
           Tangerines                                     4
           Apples                                         3
           Pears                                          3
           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
    gaps.
  - 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
  this time.
- 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
  contaminate groundwater.

                        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)
Insecticide-Rodenticide Branch
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
(703) 557-2386

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.