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Return to Gamma
cyhalothrin Adverse Effects
ACTIVITY:
Insecticide (Pyrethroid)
Systematic
Name: Cyclopropanecarboxylic
acid, 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl-, cyano(3-phenoxyphenyl)methyl
ester, (1R-(1alpha(S*),3alpha(Z)))-
Structure:
| Adverse
Effects:
Body
Weight Decrease
Dermal
Endocrine:
Suspected Disruptor
Neuromuscular
Reproductive |
Regulatory
Information
(only comprehensive for the US) |
| US
EPA Registered: |
Yes
(as of April 8, 2004) |
| US
EPA PC Code: |
128807 |
| US
Tolerances: |
CFR
180.438 |
Registered
use in
(includes only a limited list of countries)
|
US |
US
Maximum Residue Levels permitted
in food commodities
|
Lambda-cyhalothrin
and its isomer Gamma-cyhalothrin have more than 380 food tolerances,
including:
Alfalfa,
Egg, Garlic, Barley, Brassica, Cattle, Corn, Cotton, Goat,
Hog, Horse, Lettuce, Milk, Onion, Peanut, Poultry, Rice,Sheep,
Sorghum, Soybean, Sugarcane, Sunflower Seeds, Tomato, Wheat |
| Other
Names: |
Fentrol®
Nexide®
GF-317
GF-231
ProAxis
15CS
[1R-[1 ALPHA(S*),3 ALPHA(Z)]]-CYANO(3-
PHENOXYPHENYL)METHYL 3-(2-CHLORO-3,3,3-TRIFLUORO-
1-PROPENYL)-2,2-
DIMETHYLCYCLOPROPANECARBOXYLATE |
| Of
special interest: |
| PAN
Data |
April
2003: Proaxis*
15CS Product Launch in Indonesia. Organizer: PT Dow AgroSciences
Indonesia. Co-sponsor: PT Bingel Agung.
|
| Brochure
in Indonesian |
Cheminova
manufactures gamma-cyhalothrin on behalf of Pytech Chemicals,
which is a 50:50 joint venture between Dow AgroSciences and
Cheminova. Pytech Chemicals is responsible for worldwide registration
and market development activities.
Products based on gamma-cyhalothrin are marketed by Dow AgroSciences
and Cheminova´s local organisations and partners. Gamma-cyhalothrin
was launched in 2002. Gamma-cyhalothrin is marketed under the
brand names Nexide® and Fentrol®.
Ref: http://www.cheminova.com/en/insecticides/nexide/nexide.htm |
Dow
AgroSciences Study of Gamma Cyhalothrin:. First year field
performance of XDE-225 - Paper presented
June 2001. |
See
also:
Cyhalothrin (76703-62-3)
Lambda-Cyhalothrin
(91465-08-6) |
Gamma-cyhalothrin
is a single, resolved isomer of the pyrethroid insecticide
cyhalothrin, and as such shares physical, chemical, and
biological properties with both cyhalothrin and lambda-cyhalothrin,
which are mixtures of 4 and 2 isomers respectively. Gamma-cyhalothrin
is the most insecticidally active isomer of cyhalothrin/lambda-cyhalothrin,
and thus the technical gamma-cyhalothrin product may be
considered a refined form of cyhalothrin/lambda-cyhalothrin
in that it has been purified by removal of less active and
inactive isomers. Thus,
similar levels of insecticidal efficacy for gamma-cyhalothrin
can be obtained with significantly reduced application rates
as compared with either cyhalothrin or lambda-cyhalothrin.
-- The tolerance under 40 CFR 180.438 currently identifies
lambda-cyhalothrin as a 1:1 mixture of two isomers and their
epimers, one of which is the gamma isomer. The gamma isomer
is present at 42% in this mixture. By contrast in the proposed
tolerance expression the gamma isomer is present at 98%
in the mixture.
-- It is noted that
in the developmental toxicity study in the rat that the
resolved gamma
isomer is over an order of magnitude more toxic than in
cyhalothrin.
-- B. International Residue Limits
There are currently no Mexican, Canadian, or Codex MRLs
(maximum residue limits) for gamma- or lambda-cyhalothrin;
however, there are MRLs for cyhalothrin
from which lambda-cyhalothrin is derived as an enriched
isomer. A Codex MRLs of 0.2 part per million (ppm) has been
established
for pome fruits for cyhalothrin, which is inconsistent with
the proposed U.S. lambda-cyhalothrin tolerance of 0.3 ppm
for pome fruits. It is unclear if harmonization can be achieved
because residues up to 0.25 ppm were found in the U.S. trials
for apples. Codex MRLs were not established
for the other crops presently under consideration.
Ref: US EPA. Lambda-Cyhalothrin
and an Isomer Gamma-Cyhalothrin; Tolerances for Residue.
FINAL RULE. Federal
Register.
|
| US
Federal Register |
| Date
Published |
Docket
Identification No. |
Details |
| April 8,
2004 |
OPP-2004-0025 |
Pytech.
Lambda-Cyhalothrin
and Gamma-Cyhalothrin. Tolerances for Residues. FINAL
RULE. EPA is amending 40 CFR part 180 by promulgating
a new tolerance expression for the isomer form of gamma-cyhalothrin.
Gamma-cyhalothrin is the isolated active isomer of lambda-cyhalothrin
under 40 CFR 180.438. Pytech Chemicals
GmbH, 9330 Zionsville Rd., Indianapolis, IN 46268,
requested this change in tolerance expression in support of
the registration of a pesticide formulation enriched with
the gamma isomer of lambda-cyhalothrin.
EPA's previous risk
assessment on lambda-cyhalothrin (September
27, 2002,
Federal Register) is sufficient
to cover gamma-cyhalothrin. Accordingly,
a new aggregate risk assessment for gamma-cyhalothrin is not
needed.
It is noted that in
the developmental toxicity study in the rat that the resolved
gamma
isomer is over an order of magnitude more toxic than in cyhalothrin.
| Excerpts from Table
1.-- Subchronic, Chronic, and
Other Toxicity |
| Study
Type |
Results |
13-Week
Dietary - Rat
- Gamma cyhalothrin
(Guideline
No. 870.3100) |
NOAEL:
male/female =3.4/4.2 mg/kg/day
LOAEL: male/female = 6.6/8.8 mg/kg/day
(mortality in males, neuromuscular
effects in both sexes, dermatitis, and gross and microscopic
skin lesions in females). |
3-Generation
Reproduction -
Rat
Cyhalothrin
Lambda cyhalothrin
Gamma cyhalothrin
(Guideline
No. 870.3800) |
Parental
NOAEL: 1.5 mg/kg/day
Parental LOAEL: 5.0 mg/kg/day
(decreased parental body weight and body weight gain during
premating and gestation periods).
Reproductive NOAEL: 5.0 mg/kg/day
Reproductive LOAEL: Not established.
Offspring NOAEL: 1.5 mg/kg/day
Offspring LOAEL: 1.5 mg/kg/day (reduced pup weight and
weight gain during lactation). |
21-Day
Inhalation Toxicity - Rat
Lambda cyhalothrin
Cyhalothrin
Gamma cyhalothrin
(Guideline
No. 870.3465) |
NOAEL:
0.08 mg/kg/day
LOAEL: 0.90 mg/kg/day (clinical signs of neurotoxicity,
decreased body weight gains, increased incidence of punctate
foci in cornea, slight reductions in cholesterol
in females, slight changes in selected urinalysis parameters). |
Gamma
cyhalothrin
(Guideline
No.
870.3200) |
Maternal
NOAEL: 0.5 mg/kg/day
Maternal LOAEL: 2.0 mg/kg/day
(clinical signs, reduced body weight and body weight gain
and food consumption).
Developmental NOAEL: 2.0 mg/kg/day
Developmental LOAEL: Not established |
Gamma
cyhalothrin
(Guideline
No.
870.3200) |
NOAEL: male/female = 4.2/4.5 mg/kg/day
LOAEL: male/female = 8.8/10.2 mg/kg/ day.
(decreased body weight, body weight
gain, food consumption, clinical and biochemical effects) |
Chronic
Toxicity - Dog
Lambda cyhalothrin
Cyhalothrin
Gamma cyhalothrin
(Guideline
No.
None) |
NOAEL:
0.1 mg/kg/day
LOAEL: 0.5 mg/kg/day (clinical signs
of neurotoxicity).
Note: For one or two days of dosing, the NOEL is 0.5 mg/kg. |
| Excerpts from Table
2.-- Summary
of Toxicological Dose and Endpoints for Gamma-Cyhalothrin
for Use in Human Risk Assessment |
| Note: No study in this Table
references Gamma-cyhalothrin |
| Exposure
Scenario |
Study
and Toxicological Effects |
Acute
dietary general population including
(infants and children) |
Chronic
oral study in the dog (lambda-cyhalothrin)
Clinical signs of neurotoxicity
(ataxia) observed from day 2, 3 to 7 hours post dosing. |
| Chronic
dietary (all populations) |
Chronic
oral study in the dog (lambda-cyhalothrin)
Gait abnormalities observed in two
dogs. |
Short-term
dermal (1 to 30 days)
Long-term dermal (< 6 months) |
21-Day
dermal toxicity study in the rat (lambda-
cyhalothrin)
Clinical signs of neurotoxicity
(observed from day 2) and decreased body weight and body
weight gain. |
Tolerances are established
for the combined residues of the pyrethroid [gamma-cyhalothrin
(the isolated active isomer of lambda-cyhalothrin) and
its epimer (R)-'-cyano-3-phenoxybenzyl (Z)-(1R,3R)-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate
in/on the following commodities:
| Commodity |
PPM |
Commodity |
PPM |
| Alfalfa,
forage |
5 |
Pea
and bean, dried shelled,(except soybean), subgroup
See Ref. 5 |
0.10 |
| Alfalfa,
hay |
6 |
Pea
and bean, succulent shelled, subgroup
See Ref. 6 |
0.01 |
| Almond,
hulls |
1.5 |
Peanut |
0.05 |
| Apple
pomace, wet |
2.50 |
Peanut,
hay |
3.0 |
| Aspirated
grain fractions |
2.0 |
Poultry,
fat |
0.03 |
| Avocados
(imported) |
0.20 |
Poultry,
meat |
0.01 |
Brassica,
head and stem, subgroup
See Ref. 1 |
0.4 |
Poultry,
meat byproducts |
0.01 |
| Canola,
seed |
0.15 |
Rice,
grain |
1.0 |
| Cattle,
fat |
3 |
Rice,
hulls |
5.0 |
| Cattle,
meat |
0.2 |
Rice,
straw |
1.8 |
| Cattle,
meat byproducts |
0.2 |
Sheep,
fat |
3.0 |
| Corn,
grain (field and pop) |
0.05 |
Sheep,
meat |
0.2 |
| Corn,
fodder |
1.0 |
Sheep,
meat byproducts |
0.2 |
| Corn,
forage |
6.0 |
Sorghum,
grain. |
0.20 |
| Corn,
grain flour |
0.15 |
Sorghum,
grain, forage |
0.30 |
| Corn,
sweet, kernel plus cob with husks removed |
0.05 |
Sorghum,
grain, stover |
0.50 |
| Cottonseed |
0.05 |
Soybean |
0.01 |
| Dry
bulb onion |
0.1 |
Sugarcane |
0.05 |
| Egg |
0.01 |
Sunflower,
forage |
0.20 |
Fruit,
pome, group
See Ref. 2 |
0.30 |
Sunflower,
seed hulls |
0.50 |
Fruit,
stone, group
See Ref. 3
|
0.50 |
Sunflower,
oil |
0.30 |
| Garlic |
0.10 |
Sunflowers,
seed |
0.20 |
| Goat,
fat |
3.0 |
Tomato |
0.10 |
| Goat,
meat |
0.2 |
Tomato,
pomace (dry or wet) |
6.0 |
| Goat,
meat byproducts |
0.2 |
Vegetables,
fruiting, group (except cucurbits)
See Ref. 7 |
0.20 |
| Hog,
fat |
3.0 |
Vegetables,
legume, edible podded, subgroup
See Ref. 8 |
0.20 |
| Horse,
meat |
0.2 |
Wheat,
grain |
0.05 |
| Horse,
meat byproducts |
0.2 |
Wheat,
forage |
2.0 |
| Lettuce,
head |
2.0 |
Wheat,
hay |
2.0 |
| Lettuce,
leaf |
2.0 |
Wheat,
straw |
2.0 |
| Milk
fat (reflecting 0.20 ppm in whole milk |
5.0 |
Wheat,
bran |
2.0 |
Nut,
tree, group
See Ref. 4 |
0.05 |
Hop, dried cone. |
10 |
| Ref.
1 |
broccoli; broccoli, cavalo; broccoli,
chinese; brussels sprout; cabbage; cabbage, chinese mustard;
cabbage, chinese napa; cauliflower; cavalo broccolo; kohlrabi |
| Ref.
2 |
apple; apple, dried pomace;
apple, juice; apple, wet pomace;
crabapple; fruit, pome; loquat;
mayhaw; pear; pear, oriental; quince |
| Ref.
3 |
apricot; cherry,
sweet; cherry, tart;
fruit, stone; fruit, stone, except plum, prune, dried;
nectarine; peach; plum; plum, chickasaw; plum, damson;
plum, japanese;
plum, prune; plum, prune, dried;
plum, prune, fresh |
| Ref.
4 |
almond; almond, hulls; beechnut; butternut;
cashew; chestnut; chinquapin; filbert;
nut, brazil; nut, hickory; nut, macadamia;
nutmeat, processed, except peanut;
nuts; pecan; pistachio; walnut |
| Ref.
5 |
bean, adzuki; bean, broad dry; bean,
dry;
bean, kidney; bean, lablab; bean, lima dry;
bean, moth; bean, mung; bean, navybean, pink; bean, pinto;
bean, rice; bean, tepary;
bean, urd; catjang; chickpea; cowpea; guar;
lentil; lupin, grain; lupin, sweet; pea, blackeyed; pea,
crowder; pea, field; pea, field seed; pea, pigeon; pea,
southern |
| Ref.
6 |
bean, broad succulent; bean, lima succulent;
cowpea; cowpea seed;
pea, blackeyed; pea, english; pea, garden; pea, green;
pea, pigeon; pea, southern |
| Ref.
7 |
chili, postharvest; eggplant; groundcherry;
pepino; pepper; pepper, bell;
pepper, nonbell; pepper, nonbell, sweet;
tomatillo; tomato; tomato, concentrated products; tomato,
dried pomace;
tomato, paste; tomato, puree;
tomato, wet pomace; vegetable, fruiting;
vegetable, fruiting, group |
| Ref.
8 |
bean, moth; bean, runner; bean, snap;
bean, wax; bean, yardlong; jackbean;
longbean, chinese; pea, dwarf;
pea, edible podded; pea, pigeon;
pea, snow; pea, sugar snap;
soybean immature seed; swordbean |
|
| Feb 25,
2004 |
OPP-
2004-0025 |
Pytech.
Pesticide tolerance
petition; proposal to amend 40
CFR part 180 by adding gamma-cyhalothrin
to the tolerance expression of lambda-cyhalothrin.
Gamma-cyhalothrin is the isolated active
isomer of lambda-cyhalothrin.
Reproductive
and developmental toxicity.
A developmental
toxicity study in rats given gavage doses of 0,
0.1, 0.5, and 2 mg/kg/day with no developmental toxicity
observed under the conditions of the study. The developmental
no observed adverse effect level (NOAEL) is greater than 2
mg/kg/day, the highest dose tested (HDT).
The maternal NOAEL and lowest observed
adverse effect level (LOAEL) are established at 0.5 and 2
mg/kg/day, respectively, based on
reduced body weight,
body weight gain, and feed consumption.
Subchronic
toxicity.
A 90-day feeding study in rats fed doses of 0, 2.5, 10, 50,
and 100 parts per million (ppm) with
a NOAEL
of 50 ppm and a LOAEL of 100 ppm based on mortality,
decreased feed consumption, decreased body weights, and increased
relative liver and kidney weight at 100 ppm. |
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