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lambda-cyhalothrin (Spectracide Triazicide)
NYS DEC Letter - Registration of a Major Change in Labeled Use Pattern 4/03

New York State Department of Environmental Conservation
Division of Solid and Hazardous Materials

Bureau of Pesticides Management, 9th Floor
625 Broadway, Albany, New York 12233-7254
Phone: (518) 402-8788     FAX: (518) 402-9024
Website: www.dec.state.ny.us

April 4, 2003

CERTIFIED MAIL
RETURN RECEIPT REQUESTED


Ms. Kelly Loft
Senior Regulatory Specialist
Spectrum Group, Division of United Industries Corporation
P.O. Box 142642
St. Louis, Missouri 63114-0642

Dear Ms. Loft:

Re: Registration of a Major Change in Labeled (MCL) Use Pattern for the Active Ingredient Lambda-Cyhalothrin Contained in the Pesticide Products Spectracide Triazicide Brand Soil & Turf Insect Killer Granules (EPA Reg. No. 9688-181-8845) and Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate (EPA Reg. No. 9688-183-8845)

    The New York State Department of Environmental Conservation (Department) has completed review of the referenced applications. The Department's concern regarding the potential risk of toxicity to marine/estuarine organisms has been mitigated by the addition of the text "In New York State this product may not be applied to lawns within 100 feet of a coastal marsh, or stream that drains directly into a coastal marsh" to the DIRECTIONS FOR USE section of the labeling. The front panel of existing stocks of these products must be stickered with the above-specified text prior to use, distribution, sale, or offer for sale of the subject products in New York State. Furthermore, addition of the text, "People and pets should not be allowed in treated areas until spray has dried" to the Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate label is consistent with United States Environmental Protection Agency (USEPA) label guidance and serves as a precaution to further reduce exposure potential. Upon incorporation of the above-specified label text, use of the subject products, as labeled, should not pose unreasonable risks to humans or to the environmental resources of New York State. The Department accepts Spectracide Triazicide Brand Soil & Turf Insect Killer Granules (EPA Reg. No. 9688-181-8845) and Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate (EPA Reg. No. 9688-183-8845) for registration in New York State.

BACKGROUND:
    Spectracide Triazicide Brand Soil & Turf Insect Killer Granules (0.04% lambda- cyhalothrin) is labeled as an insecticide for outdoor use on lawns, spot treatment for ants and as a barrier band treatment around house foundations. Product labeling bears the statement "For outdoor use around the home only." A typical overall lawn application rate of 2 pounds per 1000 sq.ft. per application is equivalent to 0.035 pounds lambda-cyhalothrin/application. The maximum overall lawn application rate (six applications per year @ 3 pounds per 1000 sq.ft. per application) is equivalent to 0.314 pounds lambda-cyhalothrin/acre/year.

    Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate (0.5% lambda-cyhalothrin) is labeled as an insecticide for outdoor use on lawns, ornamental trees, flowers, shrubs and vegetables. Product labeling bears the statement "For outdoor use around the home only." The ready spray nozzle product lawn application rate of 1 quart product per 16,000 sq.ft. is equivalent to 0.028 pounds lambda-cyhalothrin/acre. A maximum application rate or re-treatment interval is not specified for the lawn use pattern. The vegetable application rate of 1 quart product per 19,200 sq.ft. is equivalent to 0.024 pounds lambda-cyhalothrin/acre. Application to all listed vegetables except corn (five applications per growing season) is limited to a maximum of nine applications which is equivalent to 0.213 pounds lambda-cyhalothrin/acre/growing season.

    Lambda-cyhalothrin is a component of products registered in New York State for use as an insecticide in cattle ear tags, for residual pest control in and around buildings and structures, for control of insect pests on ornamentals and turf, for control of insect pests in the commercial greenhouse, shadehouse and nursery environment and as an insecticide on various agricultural crops. In addition, Spectracide Bug Stop Home Insect Killer, a product labeled for domestic indoor use, was registered on February 24, 2003. The proposal to register pesticide products labeled for domestic outdoor use by homeowners represents a major change in labeled (MCL) use pattern for lambda-cyhalothrin.

    The subject registration package was deemed complete for purposes of technical review on October 30, 2002. Pursuant to the review timeframe specified in Environmental Conservation Law (ECL) 33-0704.2, a registration decision date of March 29, 2003 was established. By mutual agreement, the registration decision date was subsequently waived in order to accomodate the preparation and review of stickered and revised labeling submitted in response to a labeling oversight and issues identified in the ecological risk assessment.

    The Department conducted toxicological, ecological and environmental fate risk assessments for lambda-cyhalothrin and the two Triazicide formulated products.

TOXICOLOGICAL RISK ASSESSMENT:
    The formulated products Spectracide Triazicide Brand Soil & Turf Insect Killer Granules and Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate were not very toxic in acute oral, dermal or inhalation exposure studies in laboratory animals. These pesticide products were also not very irritating to the eyes or skin (tested on rabbits) nor were they dermal sensitizers (tested on guinea pigs).     The New York State Department of Health (NYSDOH) previously reviewed the toxicity of the active ingredient lambda-cyhalothrin for the pesticide products Commodore WP Insecticide and Warrior Insecticide. Lambda-cyhalothrin was mildly to moderately acutely toxic in laboratory animal studies and caused some toxic effects at low doses in chronic animal feeding studies. This chemical did not cause significant reproductive/developmental effects, but did cause some fetotoxicity. Lambda-cyhalothrin did not cause oncogenic effects and was negative in a number of genotoxicity studies.

    The USEPA classified lambda-cyhalothrin as a Group D carcinogen, not classifiable as to human carcinogenicity. The USEPA RfD Peer Review Committee derived an oral reference dose (RfD) of 0.001 milligrams per kilogram body weight per day (mg/kg/day) for lambda-cyhalothrin, based on a no-observed-effect-level (NOEL) of 0.1 mg/kg/day from a chronic dog feeding study (ataxia, muscle tremors and convulsions) and an uncertainty factor of 100.

    An updated search of the toxicological literature found a study reporting a toxicological effect from lambda-cyhalothrin that had not been noted in the studies conducted for federal registration (the studies conducted for federal registration, however, do not generally assess these parameters). In this study, exposure to lambda-cyhalothrin for seven consecutive days caused reductions in mating behaviors (e.g., mounting, ejaculation) at both dose levels tested (63 and 100 mg/kg/day). This sexual dysfunction had a rapid onset, but was found to be reversible, even during the dosing period. Also, despite the pre-coital effects, treated males reportedly did not have a decline in sperm quality or in the ability to impregnate females.

    No worker exposure and risk data were submitted in the registration package. While both product labels contain the statement "For outdoor use around the home only", indicating that they are aimed at the homeowner market, the granular formulation seems to be a product that commercial applicators may use to control lawn grubs. There is a particular incentive for commercial applicators to use granular products like Spectracide Triazicide in counties that have adopted the Neighbor Notification Law as the application of granular products is exempt from neighbor notification requirements. To address worker risks in this context, the NYSDOH used exposure estimates based on label directions and the Pesticide Handler Exposure Database (PHED). The application rate of the granular formulation is up to 30 pounds per 10,000 square feet. If it is assumed that applicators make ten such applications per day during a two-month grub control season, each applicator would handle 300 pounds of granular product daily, which is equivalent to a total use of 54.4 grams active ingredient per day. According to the estimates in the PHED database, mixer/loader/applicators using a push spreader would have a total dermal and inhalation exposure of 2.9 mg/ pound active ingredient applied. Thus, a 70 kg worker would have an exposure of 0.005 mg/kg/day. Comparing this exposure to a NOEL of 10 mg/kg/day from a 21-day dermal rat study (based on increased clinical effects and mortality, decreased body weight and food consumption), a margin of exposure (MOE) of 2,000 can be calculated. MOEs for homeowners who may apply the granular product should be considerable greater than this value. The USEPA generally considers MOEs of 100-fold or greater to be adequately protective.

    The registration package also did not contain any data on exposure and risks to homeowners that may use the liquid concentrate product. Using the PHED database and assuming that a homeowner applies 30 ounces of the product to a 10,000 square foot yard with a hose-end sprayer, the applicator would have an estimated combined dermal and inhalation exposure of about 0.005 mg/kg/day. An appropriate endpoint for acute exposures is not available, but by comparing this exposure to the NOEL of 10 mg/kg/day from a 21-day dermal rat study, an MOE of about 2,000 can be calculated.

    No data were provided on the dislodgeability of lambda-cyhalothrin residues from turf treated with the Spectracide Triazicide products. These data would be useful for assessing post-application exposure of children to treated turf areas. In the absence of such data, the NYSDOH characterized the likelihood of significant exposures. Based on the maximum application rate of Spectracide Triazicide to turf, total residues of lambda-cyhalothrin would be about 0.5 mg/square foot. If one assumes that all these residues are dislodgeable, a 13.2 kg child would have to have dermal transfer of all the residues in about a 275 square foot area each day to reach an exposure comparable to the NOEL of 10 mg/kg/day from the 21-day rat dermal toxicity study. Such an occurrence is unlikely, particularly once the residues have dried.

    There are no chemical specific federal or State drinking water/groundwater standards for lambda-cyhalothrin or its degradates. Based on its chemical structure, lambda-cyhalothrin falls under the 50 microgram per liter (_g/L) New York State drinking water standard for "unspecified organic contaminants" (10 NYCRR Part 5, Public Water Systems). Based on the USEPA's oral RfD of 0.001 mg/kg/day and the DEC Water Quality Regulation procedures for deriving surface water and groundwater standards and guidance values from non-oncogenic effects (6 NYCRR Part 702.5), an ambient water quality value for lambda-cyhalothrin is 7 _g/L. This value could be used to derive a screening value for comparison to estimate impacts to groundwater and surface water.

    Neither the Spectracide Triazicide Brand Soil & Turf Insect Killer Granules nor the Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate product was very acutely toxic. Although lambda-cyhalothrin was somewhat acutely toxic in laboratory animal studies and caused some toxic effects at low doses in chronic animal feeding studies, homeowner risks from applying these two products should be limited. Similarly, use of the granular formulation by commercial applicators is not expected to result in significant risks. Post-application exposure of children to lambda-cyhalothrin from treated lawns should also be minimal.

    An inconsistency between the labels of these two Triazicide products needed to be addressed. The granular product label contains the statement "Keep children and pets off treated area until product has been watered in and lawn is dry" under the Directions For Use section. The liquid concentrate product label does not contain such a statement. While significant risks from the labeled use of the concentrate product are not expected, a label statement such as "Keep children and pets off treated area until product is dry" would be consistent with the label of the granular product and serve as a precaution to further reduce exposure potential.

ECOLOGICAL RISK ASSESSMENT:
    Spectracide Triazicide Brand Soil and Turf Insect Killer Granules is a granular insecticide product for use on lawns, as a spot treatment for ants and a barrier band treatment around house foundations. The active ingredient is lambda-cyhalothrin, a synthetic pyrethroid which consititutes 0.04% of the product by weight. Spectracide Triazicide Brand Soil and Turf Insect Killer Concentrate, 0.5% lambda-cyhalothrin, is a liquid formulation for use on lawns, ornamental trees, flowers, shrubs, and vegetables.

    The highest labeled applications for the granular is for control of insects that dwell in the upper soil under lawns, such as billbugs and grubs. The application rate is 1 lb of formulated product per 333 ft2, which is equivalent to 23.76 g ai/acre. For control of insects that dwell in the thatch of lawns, the application rate is 1 lb of formulated product per 500 ft2, which is equivalent to 15.8 g/acre. Similarly, the highest application rates for the 0.5% liquid concentrate are also on lawns. There are a variety of application rates, depending upon the target pest species and the particular product label. The active ingredient equivalents in grams would be as follows: 5.8 g/quart; 0.73 g/4 fl oz; 0.54 g/3 fl oz; and 0.36 g/2 fl oz.

    No additional ecological toxicity data or environmental fate data were provided for these products, so the data provided for the registration of Warrior Insecticide was used to evaluate the ecological risks of lambda-cyhalothrin. Mammalian and avian risk models were not evaluated, since previous lambda-cyhalothrin modeling showed little likelihood of risk to birds or mammals.

    The Bureau of Habitat's (BoH) PONDTOX model was run using a single application rate of 0.035 lbs ai/acre; the maximum application rate was 0.07 lbs ai/acre. For most of the PONDTOX modeling, it was assumed that only 30% of the runoff water reached the test ponds. Based on Gross et.al., (1991), standard protocol for BoH modeling is to reduce the "amount of runoff water reaching the ponds" to 30% to adjust for the difference between turf treatments and agricultural treatments. Gross et.al., (1991) acknowledges that virtually no runoff can result from precipitation over well established turf. However, for risk assessment modeling purposes, it cannot be assumed that all lawns to which pesticides might be applied are well-established turf.

    Only acute aquatic toxicity was modeled because lambda-cyhalothrin degrades too quickly for chronic toxicity to be a concern. Using the lowest runoff rate of 0.25%, the single application rate of 0.035 lbs ai/acre, and assuming 50% of the applied product is lost to foliar intercept, both the LC50 and acute NOEC are exceeded for mysid shrimp (marine/estuarine invertebrates) in all three pond depths (one, three and six feet). At 60% loss to foliar intercept, only the acute LC50 is not exceeded in the six foot deep pond. At 80% loss to foliar intercept, only the acute LC50 is not exceeded in the three foot and six foot deep ponds. At 90% loss to foliar intercept, the acute LC50 is marginally exceeded in the one foot deep pond, and the acute NOEC is exceeded in the one and three foot deep ponds.

    At the maximum application rate (0.07 lbs ai/acre) and the low runoff rate (0.25%), the acute NOEC is exceeded in all pond depths, but the acute LC50 is exceeded only in the one foot pond depth. At the single application rate (0.035 lbs ai/acre) and the medium runoff rate (0.5%), the acute NOEC is exceeded in all three pond depths but the acute LC50 is exceeded only in the one foot pond depth, still assuming that 90% of the applied product is lost to foliar intercept. At the maximum application rate, only the LC50 in the six foot deep pond depth is not exceeded.

    The runoff modeling shows that in almost all of the modeled runoff scenarios, some risk to marine/estuarine invertebrates is likely to occur. The level of risks can be greatly reduced by increasing the value of the percentage of applied pesticide lost to foliar intercept, but the validity of that adjustment is questionable. Certainly on turf, all of the pesticide is intercepted by foliage. However, PONDTOX only examines the soluble fraction of applied pesticides. The solubility of lambda-cyhalothrin is 0.005 mg/L. One inch of rain falling on a 10 acre treated lawn would consist of 1,027,805 L of water. At a solubility of 0.005 mg/L, that much water could dissolve 5.139 g, or about 3% of the total applied pesticide (157 grams on a 10 acre treated lawn at the 0.035 lb ai/acre application rate). So even if studies showed lambda-cyhalothrin was 97% rainfast on foliage, a potentially toxic concentration of lambda-cyhalothrin could dissolve in runoff water. In this analysis, runoff rates of 0.25% and 0.5% of the total applied pesticide were modeled. These rates are equivalent to 0.39 g and 0.785 g of lambda-cyhalothrin respectively dissolving off treated vegetation. Studies could show that labmda-cyhalothrin was 99.5% rainfast, and this much lambda-cyhalothrin could still be dissolved off the treated grass and transported to a surface water via runoff.

    Lambda-cyhalothrin is extremely toxic to marine/estuarine invertebrates. Assuming all of the lambda-cyhalothrin was available, i.e., none was lost due to foliar intercept, adverse impacts to marine estuarine invertebrates still occur in the one and three foot deep ponds when only 1% of the runoff water is allowed to reach the ponds. Given that lambda-cyhalothrin could be up to 99.5% rainfast and enough still could dissolve off treated turf to exceed toxicity thresholds, the risks to marine estuarine species from applications of these product to lawns are significant.

    The PONDTOX model clearly shows that the use of these products on lawns at the labeled rates for surface insect control presents a risk to marine/estuarine invertebrates. Coastal marshes are very important nursery habitat areas for commercially and recreational important species. If large, estate-type lawns that bordered coastal marshes were treated with products with lambda-cyhalothrin, significant impacts could occur.

    Use of these products for ornamentals, vegetables, barrier treatments, spot treatments or crack and crevice treatments do not pose unacceptable ecological risks. These treatments are small and highly localized. Sites that might be treated, such as backyard gardens and around home (or outbuilding) foundations are also generally fairly small in total area, and are usually surrounded by some expanse of lawn turf, which would constitute an effective barrier strip. The most significant risks these products pose is the risk to marine/estuarine invertebrates from large areas of treated lawns adjacent to coastal marshes.

LITERATURE CITED

Gross, C.M., J.S. Angle, R.L. Hill, and M.S. Welterlen, 1991. Runoff and sediment losses from tall fescue under simulated rainfall. J. Environ. Qual. 20:604-607 (1991).

ENVIRONMENTAL FATE RISK ASSESSMENT:
    This risk assessment was based on a limited number of Data Evaluation Record (DER) reports on file, an Environmental Fate and Effects Division (EFED) memorandum and some study summaries. The studies were conducted in the early 1980's before Subdivision N guidelines were in effect.

Hydrolysis: At pH 5 and pH 7, there is no hydrolysis; however at pH 9, the hydrolysis half-life is 7 days.

Aqueous Photolysis: According to a study summary, after 31 days, 38-44% remained with two major degradates (1RS)-cis-3-(ZE-2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropane-carboylic acid at 13.4% and 3-phenoxybenzoic acid at 24.5%.

Soil Photolysis: Lambda-cyhalothrin is stable to photolysis on soil.

Aerobic Soil Metabolism: According to a study summary, lambda-cyhalothrin aerobically degraded with a half-life of about 30 days.

Anaerobic Soil Metabolism: Lambda-cyhalothrin anaerobically degraded with a half-life of < 30 days.

Column Leaching: Lambda-cyhalothrin and its degradates were immobile in columns of clay loam, loamy sand, coarse sand and peat soils.

Adsorption/Desorption: According to a study summary, lambda-cyhalothrin was rapidly and extensively adsorbed onto four different soils with Kocs in the range of 100,000-430,000, which is in good agreement with the 150,000 value calculated from the octanol-water partitioning coefficient.

Field Dissipation: In supplemental field dissipation studies, the reported half-lives ranged from 26-40 days. Analysis showed all but one detection was found in the 0-6 inch depth, and one detection in the 6-12 inch depth at days 0 and 7 post-treatment.

    Given the extremely high Kocs and the fact that the application rates for these two products are lower than the rate already registered for agricultural use, the subject products are not expected to impact groundwater in New York State.

MITIGATION:
    In order to mitigate the Department's concern regarding the potential risk of toxicity to marine/estuarine organisms due to runoff from large, estate-type lawns that are treated with these products, Spectrum Group proposed the following actions: 1) To sticker the front panel of existing stock of Spectracide Triazicide Brand Soil & Turf Insect Killer Granules (1 lb, 10 lb, 20 lb) and Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate with the text, "In New York State this product may not be applied to lawns within 100 feet of a coastal marsh, or stream that drains directly into a coastal marsh"; and 2) Product produced after March 20, 2003 would bear the following text under the DIRECTIONS FOR USE section of the labeling: "In New York State this product may not be applied to lawns within 100 feet of a coastal marsh, or stream that drains directly into a coastal marsh." On March 20, 2003, Spectrum Group submitted a copy of the notification to USEPA, dated March 20, 2003, regarding this labeling change together with "stickered" labeling and proposed revised labeling for the Department's review. Furthermore, the March 20, 2003 notification for Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate included the addition of the text "People and pets should not be allowed in treated areas until spray has dried" immediately following the misuse statement under the DIRECTIONS FOR USE section of the labeling.

    When used as labeled, the Triazicide products bearing updated labeling (stickered and/or revised) prohibiting application of the products to lawns within 100 feet of a coastal marsh, or stream that drains directly into a coastal marsh should not cause unreasonable adverse effects to humans or the environment. The Department hereby accepts Spectracide Triazicide Brand Soil & Turf Insect Killer Granules (EPA Reg. No. 9688-181-8845) and Spectracide Triazicide Brand Soil & Turf Insect Killer Concentrate (EPA Reg. No. 9688-183-8845) in New York State. Enclosed for your files are the Certificate of Pesticide Registration and New York State stamped-"ACCEPTED" labeling.

    Please note that a proposal by Spectrum Group, or any other registrant, to register a product containing lambda-cyhalothrin, whose labeled uses are likely to increase the potential for significant exposure to humans or impact to the environment, would constitute a major change in labeled (MCL) use pattern. Such an application must be accompanied by a new application fee and meet the requirements specified in 6 NYCRR Part 326.17.

    Please contact Samuel Jackling, Chief of our Pesticide Product Registration Section, at (518) 402-8768 if you have any questions.

Sincerely,

Maureen P. Serafini
Director
Bureau of Pesticides Management

Enclosures
cc: w/enc. - N. Kim/D. Luttinger, NYS Dept. of Health
R. Zimmerman/R. Mungari, NYS Dept. of Ag. & Markets
G. Good/W. Smith, Cornell University, PMEP
bcc: w/enc. - S. Sanford, FW&MR
PCS III, Reg. 1
PCS II's, Regions 2-9
M. Radzevich
Spectrum Group File
Chemical File
Active Ing. File
bcc: w/o enc. - L. Whitbeck
R. Hackett/Tracking Daybook
e-mail: J. Leach, NYSDOH
J. Kaplan, NYSDOH
R. MacFee, NYSDOH
T. Sinnott, FW&MR
M. Serafini
A. Lamanno
S. Jackling