Debunking Human Health Risk, APPENDIX D - LBAMspray.com

SECTION D3
TOXICITY ASSESSMENT
Table D3-13
Toxicity Profile of Lambda-Cyhalothrin
Study Type Year/Doses Results
3-Generation Reproduction–rat
(cyhalothrin)
Year oral–dog (capsule:
lambda-cyhalothrin)
Carcinogenicity –mouse
(cyhalothrin)
Chronic/Carcinogenicity - rat
(cyhalothrin)
1984/0, 0.5, 1.5, 5.0 mg/kg-d Parental/Offspring NOAEL: 1.5 mg/kg-d
Parental/Offspring LOAEL: 5.0 mg/kg-d
Decreased parental body weight and body
weight gain during premating and gestation periods and reduced pup
weight and weight gain during lactation.
Reproductive NOAEL: 5.0 mg/kg-d (HDT)
1986/0, 0.1, 0.5, 3.5 mg/kg-d NOAEL: 0.1 mg/kg-d
LOAEL: 0.5 mg/kg-d
Clinical signs of neurotoxicity.
1984/0, 3, 15, 75 mg/kg-d. NOAEL: 15 mg/kg-d
LOAEL: 75 mg/kg-d
Increased incidence of piloerection, hunched posture; decreased
body weight gain in males. Not oncogenic under conditions of study.
HDT inadequate. New study not required at this time.
1984/0, 0.5, 2.5, 12.5 mg/kg-d NOAEL: 2.5 mg/kg-d
LOAEL: 12.5 mg/kg-d
Decreases in mean body weight. Not oncogenic under conditions of
study.
Notes:
a NOAEL = no observed adverse effect level
b LOAEL = lowest observed adverse effect level from USEPA 2002a, 2004a, 2007b, 2007c; ATSDR 2003a
D3.1.3.2.5 Developmental Toxicity
Two of the studies listed in Table D3-13 summarize the results of studies in which cyhalothrin
was evaluated for developmental toxicity in rats or rabbits. Few details of those studies are
publically available, but the information provided by the USEPA (2002a, 2004a) indicates that
the maternal NOAEL was 10 mg/kg-d for both species. The developmental NOAEL was the
highest dose tested in each study; in rats, it was 15 mg/kg-d, and in rabbits, 30 mg/kg-d.
D3.1.3.2.6 Reproductive Toxicity
In a reproductive study of cyhalothrin (see Table D3-13) rats were dosed with 0, 0.5, 1.5, or 5.0
mg/kg-d over three generations. The LOAEL of 5.0 mg/kg-d elicited adverse effects in both the
parents and pups, with toxicity manifested as reduced body weight and body weight gain in the
parents, and reduced pup weight and reduced pup weight gain during lactation. Although the
USEPA (2002a, 2004a) lists the reproductive NOAEL as 5 mg/kg-d, the summary provided
indicates that the NOAEL should have been identified as the next lowest dose level of 1.5
mg/kg-d.
D3.1.3.2.7 Genotoxicity
No genotoxicity data for cyhalothrin or lambda-cyhalothrin were identified in the ATSDR
(2003a) review, or in recent USEPA pesticide tolerance documents (USEPA 2002a, 2004a,
2007b, 2007c). Genotoxicity data for other Type II pyrethroids (summarized in ATSDR 2003)
and excerpted as Table D3-14, show that the Type II pyrethroids appear to be clastogenic in
mammalian test systems. Although not all test results are consistent, as a class, this type of
pyrethroid can induce chromosomal aberrations, sister chromatid exchange, micronuclei, and
DNA fragmentation. However, the available carcinogenicity data (see following) do not indicate
that this clastogenicity is associated with tumorigenic potential.
JULY 2009 App D_HHRA_508.doc D3-31