GHS Classification Result (Revision of the past classification result)

Chemical Name:4-Amino-6-tert-butyl-3-methylthio-1,2,4-triazin-5(4H)-one, (Metribuzin)
CAS:21087-64-9

Result:
ID: 21B3015
Classifier: Ministry of Health, Labour and Welfare (MHLW), Ministry of the Environment (MOE)
Year Classified: FY2009
Reference Manual: GHS Classification Guidance by the Japanese Government (March, 2009)

PHYSICAL HAZARDS
Hazard class Classification Symbol Signal word Hazard statement Precautionary statement Rationale for the classification
1 Explosives Not applicable - - - - There are no chemical groups associated with explosive properties present in the molecules.
2 Flammable gases (including chemically unstable gases) Not applicable - - - - Solid (GHS definition)
3 Aerosols Not applicable - - - - Not aerosol products
4 Oxidizing gases Not applicable - - - - Solid (GHS definition)
5 Gases under pressure Not applicable - - - - Solid (GHS definition)
6 Flammable liquids Not applicable - - - - Solid (GHS definition)
7 Flammable solids Classification not possible - - - - No data available.
8 Self-reactive substances and mixtures Not applicable - - - - There are no chemical groups present in the molecule associated with explosive or self-reactive properties.
9 Pyrophoric liquids Not applicable - - - - Solid (GHS definition)
10 Pyrophoric solids Classification not possible - - - - No data available.
11 Self-heating substances and mixtures Classification not possible - - - - Test methods applicable to solid (melting point is <=140 degC) substances are not available (melting point: 125.5 - 126.5 degC (Pesticide safety information (Japan Crop Protection Association) (Vol. 12, No. 1 (1987)), The Society of Synthetic Organic Chemistry, Japan, Dictionary of Organic Compounds, Kodansha (1985))).
12 Substances and mixtures which, in contact with water, emit flammable gases Not applicable - - - - The chemical structure of the substance does not contain metals or metalloids (B, Si, P, Ge, As, Se, Sn, Sb, Te, Bi, Po, At).
13 Oxidizing liquids Not applicable - - - - Solid (GHS definition)
14 Oxidizing solids Not applicable - - - - The substance is an organic compound containing oxygen (but not fluorine or chlorine) which is chemically bonded only to carbon or hydrogen.
15 Organic peroxides Not applicable - - - - Organic compounds containing no bivalent -O-O- structure
16 Corrosive to metals Classification not possible - - - - Test methods applicable to solid substances are not available.

HEALTH HAZARDS
Hazard class Classification Symbol Signal word Hazard statement Precautionary statement Rationale for the classification
1 Acute toxicity (Oral) Category 4 Warning H302: Harmful if swallowed P301+P312: IF SWALLOWED: Call a POISON CENTER or doctor/physician if you feel unwell.
P264: Wash ... thoroughly after handling.
P270: Do not eat, drink or smoke when using this product.
P330: Rinse mouth.
P501: Dispose of contents/container to ...
There are seven LD50 values for rats: (2020 mg/kg (male), 2220 mg/kg (female) (Pesticide safety information (Japan Crop Protection Association) (Journal of Pesticide Science vol. 12, No. 1 (1987)), 1100 mg/kg, 1100 mg/kg (male), 1200 mg/kg (female), 1010 mg/kg and 2200 mg/kg (HSDB (2005))). 4 of 7 LD50 values correspond to Category 4.
1 Acute toxicity (Dermal) Not classified - - - - Based on a LD50 value of >2000 mg/kg for rats (ACGIH (2001)), the substance was classified as "Not classified" in JIS Classification (correspond to Category 5 or "Not classified" in GHS classification).
1 Acute toxicity (Inhalation: Gases) Not applicable - - - - Solid (GHS definition)
1 Acute toxicity (Inhalation: Vapours) Classification not possible - - - - No data available.
1 Acute toxicity (Inhalation: Dusts and mists) Classification not possible - - - - Classification not possible due to lack of data. As relevant information, a LC50 value was >0.86 mg/L for rats (ACGIH (2001)).
2 Skin corrosion/irritation Not classified - - - - There is a report that the substance was a very slight dermal irritant in a rabbit test (ACGIH (2001)). Additionally, there is a result of no irritating in a rabbit skin irritation test (Pesticide safety information (Japan Crop Protection Association) (List open for the public) (Journal of Pesticide Science vol. 12, No. 1) (1987)) and a report that single and repeated patch tests in humans showed no irritation (HSDB (2005)). Based on these information, the substance was classified as "Not classified".
3 Serious eye damage/eye irritation Not classified - - - - There was a report that the substance was a very slight eye irritant in a rabbit test (ACGIH (2001)). Additionally, there is a report that no effect on the conjunctiva or cornea was observed during the 7-day observation period in a rabbit eye irritation test (Pesticide safety information (Japan Crop Protection Association) (List open for the public) (Journal of Pesticide Science vol. 12, No. 1) (1987)). Based on these information, the substance was classified as "Not classified".
4 Respiratory sensitization Classification not possible - - - - No data available.
4 Skin sensitization Not classified - - - - There are reports of "not sensitizing" in a guinea pig test (ACGIH (2001), Pesticide safety information (Japan Crop Protection Association) (List open for the public) "Journal of Pesticide Science vol. 12, No. 1" (1987)). In addition, sensitizing potential was not observed in human patch tests (HSDB (2005)). The substance was classified as "Not classified".
5 Germ cell mutagenicity Not classified - - - - Based on negative results in a mouse dominant lethal test by oral administration (in vivo heritable mutagenicity test) (IRIS (1995)) and a Chinese hamster spermatogonium chromosomal aberration test (in vivo germ cell mutagenicity test) (IRIS (1995)), the substance was classified as "Not classified". As relevant information, there is a report of a negative rat hepatic cell unscheduled DNA synthesis test (in vivo somatic cell genotoxicity test) (EPA RED (access on Apr. 2009)). From in vitro mutagenicity tests, there is a report of a negative Ames test (Pesticide safety information (Japan Crop Protection Association) (Journal of Pesticide Science vol. 12, No. 1 (1987)).
6 Carcinogenicity Not classified - - - - Based on the classification of "A4" in ACGIH and D in EPA (1986), the substance was classified as "Not classified". In 2-year oral carcinogenicity tests in rats and mice, there were no evidences of carcinogenicity and there were no increases in tumor incidence (ACGIH (2001), EPA RED (access on Apr. 2009)).
7 Reproductive toxicity Not classified - - - - In a three-generation reproduction feeding test in rats, there was no reproductive toxicity or general toxicity (ACGIH (2001)). In a two-generation reproduction test in rats, decreased body weight gains and hypertrophy of hepatocytes were observed but the substance is considered not to affect sexual function or fertility because of a lack of report for these effects in the test report (EPA RED (access on 4 2009)). There are two developmental toxicity tests for both rats and rabbits (EPA RED (access on 4 2009), Pesticide safety information (Japan Crop Protection Association) (List open for the public) (Journal of Pesticide Science vol. 12, No. 1 (1987)). Reduced maternal body weight gains were observed and in one rabbit test, an increased incidence of abortions was observed in the high dose group. No fetal developmental toxicity including teratology was observed except for reduced ossification and skeletal variations. It is clear from the two rat reproduction tests that the substance has no reproductive toxicity effects. It is clear from the two rat and the two rabbit developmental toxicity tests that the substance has no developmental toxicity effects. The substance was classified as "Not classified".
8 Specific target organ toxicity - Single exposure Classification not possible - - - - There is a report that no pathological changes in any specific organ were observed at rat oral LD50 test (male: 2200 mg/kg, female: 2345 mg/kg) (Pesticide safety information (Japan Crop Protection Association) (List open for the public) (Journal of Pesticide Science vol. 12, No. 1) (1987)). However, classification was not possible since effects at the upper limit (2000 mg/kg) of guidance value range were not clear.
9 Specific target organ toxicity - Repeated exposure Classification not possible - - - - In a 13-week feeding test in rats (Pesticide safety information (Japan Crop Protection Association) (List open for the public) (Journal of Pesticide Science vol. 12, No. 1) (1987)), no significant adverse effects were observed at dose levels up to 1500 ppm (75 mg/kg/day). In a 2-year feeding test in dogs (EPA RED (access on Apr. 2009)), increased relative liver weight and changes in liver function (increased SGOT and SGPT levels, increased alkaline phosphatase, increased total protein, etc.) were noted at the high dose level of 1500 ppm (approximately 55 mg/kg/day). In a 2-year feeding test in rats (EPA RED (access on Apr. 2009)), toxicity along with pathological changes in the liver were noted at the high dose level of 300 ppm (14.3 - 20.4 mg/kg/day). These data were not used as the basis of classification since the degree of changes in liver function is unknown and detailed pathological lesions in the liver are not reported. In a 3-week inhalation test in rats at dose levels of 0.031 - 0.720 mg/L/6h (90-day equivalence: approximately 0.0071 mg/L/6h/day), there were no toxic effects (ACGIH (2001)). In 3-week dermal tests in rats and rabbits at a dose level of 1000 mg/kg/day, no significant toxic findings were reported. Since the exposure period for the rat inhalation and rat/rabbit dermal tests was only 3 weeks and the adequacy of the test design is questionable, classification was not possible with any exposure route.
10 Aspiration hazard Classification not possible - - - - No data available.

ENVIRONMENTAL HAZARDS
Hazard class Classification Symbol Signal word Hazard statement Precautionary statement Rationale for the classification
11 Hazardous to the aquatic environment (Acute) Category 1 Warning H400: Very toxic to aquatic life P273: Avoid release to the environment.
P391: Collect spillage.
P501: Dispose of contents/container to ...
Classified into Category 1 from its 72h-ErC50 = 0.039 mg/L for algae (Pseudokirchneriella subcapitata) (Test for the Ecological Effect of Chemical Substances (Ministry of the Environment), 1999)
11 Hazardous to the aquatic environment (Long-term) Category 1 Warning H410: Very toxic to aquatic life with long lasting effects P273: Avoid release to the environment.
P391: Collect spillage.
P501: Dispose of contents/container to ...
Classified into Category 1 since its acute toxicity is Category 1 and it is estimated not to be rapidly degradable (BIOWIN).
12 Hazardous to the ozone layer Classification not possible - - - - This substance is not listed in Annexes to the Montreal Protocol.


NOTE:
* Classification was conducted by relevant Japanese Ministries in accordance with GHS Classification Guidance for the Japanese Government, and is intended to provide a reference for preparing GHS labelling and SDS for users.
* This is a provisional English translation of classification results and is subject to revision without notice.
* The responsibility for any resulting GHS labelling and SDS referenced from this site is with users.

Reference:
Reference Manual

Definitions / Abbreviations

Model Label by MHLW

MHLW Website (in Japanese Only)

Model SDS by MHLW

MHLW Website (in Japanese Only)


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