Chlorothalonil

Substance overview Plus
Name:
Chlorothalonil
CAS Number:
1897-45-6
Synonyms:
1,3-Benzenedicarbonitrile, 2,4,5,6-tetrachloro-, Isophthalonitrile, tetrachloro-, Tetrachloroisophthalonitrile
Approval number:
HSR002825, Approved with controls
UN Class:
 
UN Number:
 
Molecular weight:
265.89
Relative density:
1.7
Water solubility:
0.6 mg/L
Classification Acute Tox. 2 Plus
Classification route species:
(inhalation)
Classification description:
H330: Fatal if inhaled.
Classification key study:

Oral Route
LD50 Rat oral > 10 g/kg
[Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. II-317]**PEER REVIEWED** [HSDB]
[begin: CG on 2006/03/06 at 11:31]
The oral LD50 exceeded 10,000 mg/kg (Toxicity Category IV). Clinical signs of toxicity
included epistasis, lacrimation, dyspnea, vocalization, ataxia and tremors (MRID 00094941).
[USEPA REDS Review of Chlorothalonil]
[end: CG on 2006/03/06 at 11:31]

Inhalation Route
SPECIES:
ENDPOINT: LC50
VALUE: 0.0925 mg/L
REFERENCE SOURCE: (MRID 00094942). [US EPA REDS]

Dermal Route
LD50 Albino rat acute dermal > 10,000 mg/kg
[Verschueren, K. Handbook of Environmental Data of Organic Chemicals. 2nd ed. New York, NY: Van Nostrand Reinhold Co., 1983. 386]**PEER REVIEWED** [HSDB]
[begin: CG on 2006/03/06 at 11:35]
The dermal LD50 also exceeded 10,000 mg/kg (Toxicity Category IV). Signs of toxicity included
diarrhea, lacrimation, reduced muscle tone and erythema (MRID 00094940).
[end: CG on 2006/03/06 at 11:35]

Classification Eye Damage 1 Plus
Classification route species:
 
Classification description:
H318: Causes serious eye damage.
Classification key study:

Skin Irritation
SPECIES: Rabbit
RESULT: In a dermal irritation study, slight erythema was seen in some rabbits at 72 hours with the effects clearing by day 4.
REFERENCE SOURCE: [USEPA REDS review of chlorothalonil]

Eye Irritation
SPECIES: Rabbit
RESULT: Instillation of chlorothalonil (96%) to rabbit eyes resulted in severe irritation with persistent corneal opacity, iris effects, and conjunctival irritation (MRID 00246769). Another test with rabbits found irritation and corneal opacity (MRID 00030350). Chlorothalonil is considered corrosive (Toxicity Category I).
REFERENCE SOURCE: [US EPA REDS]

Classification Skin Sens. 1 Plus
Classification route species:
 
Classification description:
H317: May cause an allergic skin reaction.
Classification key study:
Contact Sensitisation
SPECIES: Human
RESULT: Patch testing indicated that 10-28% of 88 Japanese farmers were sensitive to chlorothalonil and other pesticides; 35 had acute dermatitis. In some cases, photosensitization was involved.
REFERENCE SOURCE: [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer,1972-PRESENT. (Multivolume work).,p. V30 324 (1983)]**PEER REVIEWED** [HSDB]
Classification Carc. 2 Plus
Classification route species:
 
Classification description:
H351: Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routs of exposure cause the hazard>.
Classification key study:
Key information:
Summary of Data Reported and Evaluation
5.1 Exposure data
Exposure to chlorothalonil may occur during its production and during its application as a fungicide, bactericide and nematocide. It has been detected in some foods.
5.2 Human carcinogenicity data
No data were available to the Working Group.
5.3 Animal carcinogenicity data
Chlorothalonil was tested by oral administration in the diet in three experiments in mice and three experiments in rats. It produced renal tubular tumours (adenomas and carcinomas) in males of each species and in female rats. The incidences of forestomach papillomas and carcinomas were increased in males and females of each species.
5.4 Other relevant data
Chlorothalonil is metabolized in rats by conjugation to glutathione in the gastrointestinal tract and liver. After biliary excretion, uptake and metabolism of these conjugates in the kidney by the action of g -glutamyl transpeptidase and cysteine-conjugate b -lyase results in the production of di- and tri-thiols, which are thought to be responsible for the toxicity seen in the kidney. Sustained cytotoxicity and the resultant regenerative response in the kidney are found in conjunction with tumour formation after long-term exposure.
There may be less activity of g -glutamyl transpeptidase and cysteine-conjugate b -lyase in humans than in rats.
Forestomach tumours produced by chlorothalonil were associated with squamous hyperplasia and local irritation.
No data were available on reproductive or developmental effects.
No data were available on the genetic and related effects of chlorothalonil in humans or in rodents in vivo. In one study, 8-oxydeoxyguanosine products were observed in the livers of mice exposed in vivo. There is some evidence for genotoxicity in mammalian cells in vitro. Chlorothalonil was not mutagenic to bacteria.
5.5 Evaluation
There is inadequate evidence in humans for the carcinogenicity of chlorothalonil.
There is sufficient evidence in experimental animals for the carcinogenicity of chlorothalonil.
Overall evaluation
Chlorothalonil is possibly carcinogenic to humans (Group 2B) [IARC]

Classification STOT Rep. Exp. 1 Plus
Classification route species:
 
Classification description:
H372: Causes damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
Classification key study:
Repeated dose toxicity:

Oral Route
Value: 3 mg/kg bw/day
Primary Organ Effected: Renal toxicity (Kidney)
Secondary Organ(s) Effected: Hepatotoxicity (liver)
Weight loss/metabolic
2-Year Dog Feeding
Study
LEL: 120 ppm (converted to 3 mg/kg/day)
Diamond Shamrock
Chemical, 1970a
--------------------------------------------------------------------------------
*Conversion Factors: 1 ppm diet = 0.025 mg/kg/day
Groups of eight male and eight female dogs were fed 0, 60, and 120 ppm
chlorothalonil for 2 years. Renal tubular epithelial vacuolation and
pigmentation were observed at 120 ppm. Data taken from the isomer chlorothalonil, ID 2122, CAS 1897-45-6
[IRIS]

Classification Aquatic Acute 1 Plus
Classification route species:
 
Classification description:
H400: Very toxic to aquatic life.
Classification key study:
Bioaccumulation: Bioaccumulative: No
Bluegill sunfish exposed to 8 µg 14C-chlorothalonil/litre in a flow-through system for 30 days showed a plateau of 14C uptake within 14 days. The residues in whole fish at 30 days were 264 times the water concentration.
Chlorothalonil (EHC 183, 1996) http://www.inchem.org/documents/ehc/ehc/ehc183.htm>
[INCHEM]

Biodegradation in water: not biodegradable
Classification Aquatic Chronic 1 Plus
Classification route species:
 
Classification description:
H410: Very toxic to aquatic life with long lasting effects.
Classification key study:
Bioaccumulation: Bioaccumulative: No
Bluegill sunfish exposed to 8 µg 14C-chlorothalonil/litre in a flow-through system for 30 days showed a plateau of 14C uptake within 14 days. The residues in whole fish at 30 days were 264 times the water concentration.
Chlorothalonil (EHC 183, 1996) http://www.inchem.org/documents/ehc/ehc/ehc183.htm>
[INCHEM]

Biodegradation in water: not biodegradable
Long term toxicity to invertebrates: Endpoint: [other]
Value: 0.032 mg/L

Classification Hazardous to soil organisms, Hazardous to terrestrial vertebrates Plus
Classification route species:
 
Classification description:
 
Classification key study: