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cyfluthrin (Baythroid) Registration of a Major Change in Labeling 3/96

New York State Department of Environmental Conservation
Division of Solid & Hazardous Materials
50 Wolf Road, Albany, New York 12233-7250
Phone 518-457-6934 FAX 518-457-0629

March 28, 1996

Douglas A. Spilker, Ph.D.
Regulatory Affairs Specialist
Registrations Department
Bayer Agriculture Division
Bayer Corporation
84 00 Hawthorn Road
P.O. Box 4913
Kansas City, MO  64120-0013

Dear Dr. Spilker:

Re:  Registration of a Major Change in Labeling for Baythroid 2
     Emulsifiable Pyrethroid Insecticide (EPA Reg. No. 3125-351)

We have accepted your application to register a major change in labeling 
for the referenced pesticide product in New York State.  The product, 
Baythroid 2 Emulsifiable Pyrethroid Insecticide, contains the active 
ingredient cyfluthrin. Previous to this registration, cyfluthrin was 
registered in New York State only for use as an insecticide on trees, 
ornamentals and home lawns.

Baythroid (cyfluthrin) is accepted for registration in New York State to 
control insect pests on cotton, carrots, peppers, radishes and tomatoes. 
The product is federally restricted due to its toxicity to fish and 
aquatic organisms; therefore, its sale, use and distribution in New York 
State are limited to certified applicators or persons under their direct 

We reviewed the application and data submitted in support of this 
registration and concluded that use of Baythroid as labeled is not 
likely to result in significant adverse impacts to human health or the 
environment in New York State.

Cyfluthrin does not appear to have the properties of a chemical with 
leaching potential.  There are no chemical-specific federal or State 
drinking water/groundwater standards for cyfluthrin.  Based on its 
chemical structures cyfluthrin falls under the 5 0 micrograms/liter New 
York State drinking water standard for "unspecified organic 
contaminants" (1ONYCRR Part 5 - Public Water Systems).

Our review revealed no significant toxicological concerns from the use 
of cyfluthrin on the listed vegetables.  The United States Environmental 
Protection Agency (USEPA) established tolerances for cyfluthrin of 0.2 
parts per million (ppm) in or on carrots and tomatoes, 0.5 ppm in or on 
peppers, and l.0 ppm in or on radishes.  The USEPA estimated that the 
Theoretical Maximum Residue Contribution (TMRC) from established 
tolerances was 0.0027 mg/kg/day for the general population (ll percent 
of the USEPA reference dose).  Residue data submitted indicate that 
cyfluthrin residues on crops treated at the maximum labeled rate are 
generally less than or equal to established tolerances.

In regard to ecological effects, Baythroid, when used as labeled, has 
the potential to cause acute toxicity to aquatic invertebrates and 
limited acute toxicity to fish.  We ran the AQUATOX model using the 
following data gathered from the mesocosm study and/or the two runoff 
studies submitted by Bayer Corporation in support of this application: 
0.044 lbs. active ingredient/acre as the single application rate; 0.102 
lbs. active ingredient/acre as the maximum application rate; and 0.25% 
runoff concentration.  At the maximum application rate, the runoff 
concentration exceeded the daphnia NOEL at all three depths (one, three, 
and six feet), the daphnia LC50 at the one- and three-foot depths, the 
bluegill NOEL at the one- and three-foot depths, and the rainbow trout 
NOEL at the one-foot depth.

The submitted studies, however, provided several factors that would 
mitigate the potential for acute toxicity to aquatic life.  Cyfluthrin 
has a high Kow and adsorbs strongly to soils and sediments.  It degrades 
fairly rapidly on soil, with a half- life between three to 16 days, 
depending on the soil type.  In water, the half-life is only 4 7 hours. 
Because of the rapid degradation and strong adherence to soil particles, 
cyfluthrin has been shown to have minimal impacts on aquatic life.  The 
mesocosm study demonstrated that while the abundance of some sensitive 
invertebrates was impacted, the overall invertebrate community was not, 
and the sensitive invertebrates showed recovery by the end of the test. 
Therefore, the use of Baythroid should not be harmful to fish and 
wildlife resources in New York State.

The label accepted for registration in New York State is the federally-
registered label as submitted. Any amendments and/or revisions to this 
label must be accepted by this Department prior to distribution in New 
York State.  The Certificate of Registration and the New York State 
stamped "ACCEPTED" label for Baythroid 2 Emulsifiable Pyrethroid 
Insecticide are enclosed for your records.


Norman H. Nosenchuck, P.E.
Division of Solid & Hazardous Materials

cc: w/enc. - D. Rutz/B. Smith, Cornell University, PMEP
             N. Rudgers/R. Mungari, NYS Dept. of Ag. & Mkts.
             N. Kim/T. Grey, NYS Dept. of Health