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cyromazine (Larvadex,Trigard) Chemical Fact Sheet 12/86

Fact Sheet
Name of Chemical: Cyromazine
Reason for Issuance: New Chemical
Date Issued: December  1986
Fact Sheet Number: 105

                     1.  DESCRIPTION OF CHEMICAL

Generic Name:  N-cyclopropyl-1,3,5-triazine-2,4,6 triamine
Common Name:   Cyromazine
Trade Name:    Larvadex Technical and Premix (poultry feed through)
               Trigard (celery and lettuce)
EPA Shaughnessy Code:  #121301
Chemical Abstracts Service (CAS) Number:  66215-27-8
Year of Initial Registration:  1984
Pesticide Type:  Insect Growth Regulator
Chemical Family:  Triazine
Producer (U.S.only):  Ciba-Geigy Corporation

                    2.  USE PATTERN AND FORMULATION

A.  Application Site:  Feed through for poultry - caged layers only.
    The active ingredient is passed through the chicken, leaving a
    residue in the manure that controls the growth of the fly larvae
    developing there.

    Type of Formulation:  Premix - a coarsely ground powder

    Application Rates:  Mix 1 lb of Larvadex (0.3% Premix) per ton of
    feed for control of housefly and soldier fly; for lesser.housefly,
    mix 3.33 lbs of Larvadex (0.3% Premix) per ton of feed.

B. Application sites- Celery and lettuce

   Type of Formulation, Wettable Powder - this product is only packaged
   in 2 lb. water soluble bags

   Application Rates - One 2 lb. package mixed in the appropriate
   amount of water will treat 12 acres - this is 1/6 lb. Trigard 75W per

                         3.  SCIENCE FINDINGS

Based on calculations and environmental chemistry data, there is no 
expectation for unreasonable adverse effects to nontarget organisms from 
the proposed uses of cyromazine. Sufficient data are available to 
support conditional registration of cyromazine as an insect growth 
regulator in and around poultry houses and for use on celery and 

Chemical Characteristics of the Technical Chemical

Physical state: crystalline solid
Color:  white
Odor:  odorless
Boiling point:  Not applicable
Melting point:  220 degrees to 222 degrees C
Flammability:  Not applicable
Solubility in water: 1.1%

There are no unusual handling characteristics.

Toxicology Characteristics

- Acute oral LD (rat); LD = 3387-mg/kg
  Toxicology Category III

- Acute oral LD (mouse); LD = 2029 mg/kg
  Toxicology Category III

- Acute oral LD (rabbit); LD = 1467 mg/ kg
  Toxicology Category III

-  Acute dermal LD (rat); LD >3100 mg/kg
   Toxicity Category III

- Primary- dermal irritation (rabbit); PIS = 1.1/8 0
  Toxicology Category IV

- Primary eye irritation (rabbit); Negative
  Toxicology Category IV

- Skin sensitization (guinea pig): nonsensitizing
  Toxicology Category: N/A

- Mutagenic (Salmonella): Negative for point mutations in TA1535,
  TA1537, TA98, TA100 with and without activation

- 90-Day feeding (dog): NOEL = 300 ppm: LEL = 1000 ppm;
  levels tested = 0, 30, 300, and 3000 ppm.

- 6 months feeding (dog); NOEL = 30 ppm;  LEL = 300 ppm;
  levels tested = 30, 300 and 300 ppm.

- Teratology (rat); Negative for teratogenic effects up to and including
  1000 my/kg/day.

- Teratology (rabbit); NOEL for teratogenic effects at 5 mg/kg/day:
  Maternal NOEL at 10 mg/kg/day.

- 2-Generation reproduction:  Systemic NOEL = 30 ppm;
  systemic LEL = 1000 ppm; levels tested = 0, 30, 100 and 3000 ppm.

- 2-Year feeding/Oncogenicity (rat); NOEL = 30 ppm:
  LEL = 300 ppm; negative for oncogenic.effects at 3000 ppm (HDT)

- Mutagenic (dominant and nucleus): negative

Physiological and Biochemical Behavioral Characteristics

- Mechanism of pesticidal action:  Cyromazine is not a cholinesterase
  inhibitor.  As an insect growth regulator, cyrozine exerts its toxic
  action by affecting the nervous system of the immature stages (larvae)
  of certain insects.

Environmental Characteristics

- Cyromazine is practically nontoxic (acutely) to mammals and birds.
  Exposure estimates for these organisms are <0.05 ppm.  Acute toxicity
  for birds is 1785 ppm maximum.  Safety factor is 105-106 for birds.
  Acute toxicity for mammals is 1000 ppm maximum.  Safety factor is
  again 105 - 106.  A summary of the environmental chemistry factors
  to be considered in this hazard assessment indicates that:

  - Cyromazine is stable to hydrolysis; photolysis is the
    dominant physico-chemical degradation mechanism.

  -  Cyromazine is not expected to build up in soils; at 5 ppm in
     chicken manure (5 tons/A) <0.05 ppm cyromazine is expected in
     soils.  Half lives in soil-manure are 1 year (lab) and 12 weeks

  - Cyromazine is not expected to build up in plants or crops; <0.05 ppm
    is expected from typical chicken manure applications.

  - Cyromazine is not expected to build up in animal tissues; fish
    bioconcentration factors are expected to be between 0.2-7.8X.

  - Cyromazine has no detrimental effects on soil microorganisms.

  - Cyromazine has a low to moderate mobility in sandy or loam sand

Ecological Characteristics:

Avian Acute Oral LD50

   Species                    LD50

   Mallard duck             >2510 mg/kg
   Bobwhite quail           1785 (1444-2206) mg/kg
   Peking duck              >6000 mg/kg

Avian.- Dietary LC50

   Species                    LD50

   Mallard duck.            >5620 ppm
   Bobwhite quail           >5620 ppm

Fish Acute LC50 (96-hr)

   Species                     96 hr LC50

   Bluegill sunfish              >89.7 mg/l
   Rainbow trout                 >87.9 mg/l
   Channel catfish               >92.4 mg/l

Aquatic Invertebrate LC50

   Species                     48 hr LC50

   Daphnia magna              >97.8 mg/l

Summary of Tolerances    40 CFR S180.414

   Commodities                             Parts Per Million

Eggs .............................................0.25
Meat of Poultry ..................................0.05
Fat of Poultry ...................................0.05
Meat by-products of Poultry ......................0.05
Poultry feed (see 21 CF)...........................5.0
Celery ..........................................10.0
Lettuce ......................................... 5.0


Use classification.:  N/A

Use, formulation or geographical restrictions:  Larvadex has been 
approved for use in poultry feed for caged layers as a feed through 
pesticide to control flies in the manure. Trigard has been approved for 
use on celery and lettuce as a conventional spray on emulsion to control 
leafminers. Products containing cyromazine are to be stored in cool, dry 
places.  There are no geographical restrictions or unique warning 
statements required on the label.

                   5. SUMMARY OF MAJOR DATA GAPS

- Toxicology:  None
- Environmental Fate:  Applicator Exposure Study
- Environmental Safety:  None
- Residue Chemistry:  None

                      6. CONTACT PERSON AT EPA

Arturo E. Castillo, PM-17
Insecticide-Rodenticide Branch (TS-767)
401 M Street  SW.
Washington, DC  20460
(703) 557-4414

DISCLAIMER:  The information presented in this Chemical Information Fact 
Sheet is for informational purposes only and may not be used to fulfill 
data requirements for pesticide registration and reregistration.