Lexikon
Chemical Name: 2-cyano-N-[(ethylamino)carbonyl]-2-(methoxyimino) acetamide
Common Name: Cymoxanil
Trade Name: Curzate 60 DF
Chemical Abstracts Service (CAS) Number: 57966-95-7
Pesticide Type: Fungicide
Cymoxanil is applied as a seed treatment to cut potato seed pieces or as a foliar application to the plants to control late blight (Phytophthora infestans). The end-use product, Curate 60 DF is formulated as a 60% dry flowable formulation. Curate 60 DF is to be used only in combination (tank mixed) with other protectant fungicides such as mancozeb, chlorothalonil, triphenyltin hydroxide, or metiram. As a seed treatment, the product is applied by dipping the 2 seed pieces in a concentrated slurry or by mist seed treating equipment.
Acute Toxicity: The acute toxicity data show that this chemical is not acutely toxic by the oral, inhalation, and dermal routes of exposure.
Subchronic Toxicity: In a subchronic oral study in mice, the NOEL was 8.25 mg/kg/day for males and 11.3 mg/kg/day for females. In a subchronic oral toxicity in dogs, a NOEL was not established and the LOEL was 3 mg/kg/day. In a subchronic oral toxicity/neurotoxicity study in rats, the NOEL was 47.6 mg/kg/day in males and 59.9 mg/kg/day for females. In a 28 day dermal toxicity study, the NOEL was 1000 mg/kg/day (highest dose tested).
Chronic Toxicity: In a combined chronic/carcinogenicity study, the NOEL was 4.08 mg/kg/day for males and 5.36 mg/kg/day of females. In a chronic toxicity study in dogs, the NOEL was 5.7 mg/kg/day for males and 3.1 mg/kg/day for females.
Carcinogenicity: Cymoxanil showed no evidence of carcinogenic potential and was classified as a “Not Likely” carcinogen.
Developmental Toxicity: In a prenatal developmental toxicity study in rats, the maternal and developmental NOEL was 10 mg/kg/day. In a prenatal developmental toxicity study in rabbits, the maternal and developmental NOEL was 16 mg/kg/day. In another prenatal developmental toxicity study in rabbits, the maternal and developmental NOEL was 4 mg/kg/day.
Reproductive Toxicity: In a two-generation reproduction study in rats, the parental systemic NOEL was 100 ppm (6.5 mg/kg/day for males and 7.9 mg/kg/day for females) and the offspring NOEL was 100 ppm.
Neurotoxicity: In the neurotoxicity portion of the subchronic/neurotoxicity study in rats, the NOEL for neurotoxicity was 224 mg/kg/day for males and 333 mg/kg/day for females. In the combined chronic toxicity/carcinogenicity study in rats, sciatic nerve axon/myelin degeneration was reported in females at dose levels of 30.3 and 90.1 mg/kg/day and hyperactivity and aggressiveness were reported in males at 30.3 and 90.1 mg/kg/day. In the carcinogenicity study in mice, absolute brain weight was decreased in both sexes at 216/298 mg/kg/day and 446/582 mg/kg/day for males/females. No evidence of developmental anomalies of the fetal nervous system were observed in the prenatal developmental toxicity studies in either rats, or rabbits, at maternally toxic oral doses up to 25 and 32 mg/kg/day. In addition, there was no evidence of behavioral or neurological effects on the offspring in the two-generation reproduction study in rats.
Mutagenicity: Gene mutation assays in bacterial and mammalian cells, a mouse micronucleus assay and an in vivo/in vitro unscheduled DNA synthesis (UDS) assay in rats were negative. An in vitro unscheduled DNA synthesis assay-primary rat hepatocytes and a chromosome aberrations in human lymphocytes assay were positive. However, the negative results from the mouse bone marrow micronucleus assay support the lack of carcinogenic effect in the rat and mouse longterm feeding study.
Reference Dose: The Reference Dose (RfD) for cymoxanil is 0.013 mg/kg/day. This value is based on the NOEL of 4.08 mg/kg/day from a chronic feeding study in rats. The Uncertainty Factor of 300 was used to account for interspecies extrapolation, intraspecies variation and the enhanced sensitivity of infants and children.
Classified based on the Globally Harmonised System (GHS):
- Acute Tox 4, H302
- Skin Sens 1A, H317
- STOT RE Cat 2, H373
- Repr. Cat 2, H361d
- Aquatic Acute 1, H400, M=1
- Aquatic Chronic 2, H411
Source: http://www.epa.gov/opprd001/factsheets/cymoxanil.pdf