NITE - Chemical Management Field

Latest GHS Classification Results by the Japanese Government (edited by NITE)

GENERAL INFORMATION

Item	Information
CAS RN	593-74-8
Chemical Name	Dimethyl mercury
Substance ID	m-nite-593-74-8_v1
Download of Excel format	Excel file

REFERENCE INFORMATION

Item	Information
Guidance used for the classification (External link)	To Guidance List
UN GHS document (External link)	To UN GHS document
FAQ（GHS classification results by the Japanese Government）	To FAQ
List of Information Sources (Excel file)	List of Information Sources
List of Definitions/Abbreviations	Definitions/Abbreviations
Sample Label by MHLW (External link)	To Workplace Safety Site (MHLW)
Sample SDS by MHLW (External link)	To Workplace Safety Site (MHLW)
OECD/eChemPortal (External link)	To OECD/eChemPortal (External link)

PHYSICAL HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification	Classification year (FY)	GHS Classification Guidance for the Japanese Government
1	Explosives	Not classified (Not applicable)	- -	-	-	There are no chemical groups present in the molecule associated with explosive properties.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
2	Flammable gases	Not classified (Not applicable)	- -	-	-	"Liquids" according to GHS definition.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
3	Aerosols	Not classified (Not applicable)	- -	-	-	Not an aerosol product.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
4	Oxidizing gases	Not classified (Not applicable)	- -	-	-	"Liquids" according to GHS definition.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
5	Gases under pressure	Not classified (Not applicable)	- -	-	-	"Liquids" according to GHS definition.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
6	Flammable liquids	Category 2	Danger	H225	P303+P361+P353 P370+P378 P403+P235 P210 P233 P240 P241 P242 P243 P280 P501	From data of a flash point of 5 degrees C (methods; unknown), and a boiling point of 93-94 degrees C (ICSC (2003)), it is estimated that it corresponds to Category 2 in a prescribed test method.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
7	Flammable solids	Not classified (Not applicable)	- -	-	-	"Liquids" according to GHS definition.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
8	Self-reactive substances and mixtures	Not classified (Not applicable)	- -	-	-	There are no chemical groups present in the molecule associated with explosive or self-reactive properties.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
9	Pyrophoric liquids	Classification not possible	- -	-	-	Due to no data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
10	Pyrophoric solids	Not classified (Not applicable)	- -	-	-	"Liquids" according to GHS definition.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
11	Self-heating substances and mixtures	Classification not possible	- -	-	-	No established test method suitable for liquid substances.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
12	Substances and mixtures which, in contact with water, emit flammable gases	Not classified	- -	-	-	From the observation result of insoluble in water (IARC58 (1993)), it is estimated that it does not react vigorously with water.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
13	Oxidizing liquids	Not classified (Not applicable)	- -	-	-	It is an organic compound that does not contain oxygen, fluorine, or chlorine.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
14	Oxidizing solids	Not classified (Not applicable)	- -	-	-	"Liquids" according to GHS definition.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
15	Organic peroxides	Not classified (Not applicable)	- -	-	-	It is an organic compound that does not contain bivalent -O-O- structure in the molecule.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
16	Corrosive to metals	Classification not possible	- -	-	-	Due to no data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
17	Desensitized explosives	-	- -	-	-	-	-	-

HEALTH HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification	Classification year (FY)	GHS Classification Guidance for the Japanese Government
1	Acute toxicity (Oral)	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
1	Acute toxicity (Dermal)	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
1	Acute toxicity (Inhalation: Gases)	Not classified (Not applicable)	- -	-	-	"Liquids" according to GHS definition.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
1	Acute toxicity (Inhalation: Vapours)	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
1	Acute toxicity (Inhalation: Dusts and mists)	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
2	Skin corrosion/irritation	Classification not possible	- -	-	-	The classification is not possible due to lack of data. Besides, it is written that alkyl mercury compounds are severely irritating to skin (HSDB (Access on August 2015)).	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
3	Serious eye damage/eye irritation	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
4	Respiratory sensitization	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
4	Skin sensitization	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
5	Germ cell mutagenicity	Classification not possible	- -	-	-	The classification is not possible due to lack of data. As for in vivo, a chromosomal aberration test in mouse oocytes after intravenous administration was negative (IARC 58 (1993)). As for in vitro, a chromosomal aberration test in cultured human lymphocytes was positive (IARC 58 (1993)), and a chromosomal aberration test in cultured Chinese hamster cells was negative (ATSDR (1999)). It is written that a positive result in a chromosomal aberration test using Chinese hamster cells mentioned in the previous classification is that on only one dose (ATSDR (1999)).	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
6	Carcinogenicity	Category 2	Warning	H351	P308+P313 P201 P202 P280 P405 P501	There is no carcinogenicity information in humans. As for experimental animals, it is written that in carcinogenicity tests in rats or mice in diet administration of methylmercury chloride, no tumors were observed in rats, but an increased incidence of adenoma or adenocarcinoma of renal tubules was found in males in all of the three mouse test results (IARC 58 (1993)). Namely, it is written that in the other test in mice in diet administration of methylmercury chloride, a significantly increased number of kidney tumors was observed in male mice, and that (a few) kidney tumors were found in male and female mice treated with testosterone propionate after gonadectomy (increased kidney tumors did not occur in male and female mice not dosed of testosterone after gonadectomy) (IARC 58 (1993)). Based on these results, IARC classified it in Group 2B (IARC 58 (1993)). After this, there are no classification results in carcinogenicity by other organizations, and no information supporting evidence of carcinogenicity in humans was obtained. Therefore, the substance was classified in Category 2. in this hazard class.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
7	Reproductive toxicity	Category 1A,	Danger	H360 H362	P308+P313 P201 P202 P260 P263 P264 P270 P280 P405 P501	There are no data on reproductive toxicity effects limited to this substance (dimethylmercury). However, it is written in Handbook on the Toxicology of Metals (4th, ed., 2015) that this substance is effectively absorbed by an inhalation or dermal route and is converted to "methylmercury (MeHg)" in vivo, and from a symptomatologic and toxicokinetic point of view, dimethylmercury poisoning is equivalent to the symptoms occurred after exposure to methylmercury compounds, based on the signs described in a few fatal poisoning exposure cases. It is written that by estimating from the case of person who developed delayed neurological symptoms 5 months after single exposure to this substance, absorbed dimethylmercury is distributed and accumulated in fat tissue, and demethylated form may be gradually generated (Handbook on the Toxicology of Metals. 4th. ed., Volume II. pp. 1061 (2015)). Therefore, it was judged that reproductive toxicity information of "methylmercury" is usable for the classification in this hazard class, hereafter, it will be classified by referring to the information described in JECFA FAS (2007), ATSDR (2013), and ACGIH (7th, 2001) on reproductive/developmental toxicity effects of methyl mercury as well as the information mentioned in the official position of the country on "fetal Minamata disease" in Japan. In assessment of health effects by methylmercury in humans at a joint WHO/FAO expert committee, an investigation research on pregnant women and children exposed to this substance in the Faroe Islands, and from the investigation research on children who were prenatally and postnatally, or only postnatally exposed in Japan and Iraq, as sensitivity to neurobehavioral toxic effects such as slight decrease in motor control function and visual disorder that occur after birth, there is no difference in vulnerability between prenatal exposure from a stage of fetuses in maternal uterus and postnatal exposure from a stage of infants, and the committee concluded that exposure to methylmercury by ingestion of contaminated fish and so on should be strictly curbed in pregnant women and infants, especially as a high-risk group (JECFA FAS 58 (2007)). Moreover, as for humans, it is written that in a population of women exposed to methylmercury during pregnancy in Michigan in the US, a women subgroup having preterm delivery with a gestation period of less than 35 weeks tended to have hair mercury levels above the 90th percentile (0.55 to 2.5 micro g/g) of those in a subgroup of women who delivered after a full gestation period of 37 weeks or longer (ATSDR addendum (2013)). On the other hand, for methylmercury, a causality of diaplacental methylmercury poisoning called as fetal Minamata disease and newborn Minamata disease was clarified. Namely, neurological symptoms are observed in pregnant women who are exposed to methylmercury by ingesting fish and seafood contaminated with organic mercury and progressed from sensory disturbance gradually to ataxia and constriction of the visual field, and children born show cerebral-paralysis-like signs such as intelligence impairment, disturbance of development, speech difficulty, gait disorder, and posture change, which tend to be severer than those of adults. It is written that even at levels of methylmercury which do not always cause clinical signs in mothers, fetuses are more likely to have effects of Minamata disease because they are more sensitive due to low excretion of methylmercury (Summary of Minamata disease problem (2015), edited by Environmental Research Office, Research Bureau, the House of Representatives, June (2015)). Besides these, it is written that a major target organ of methylmercury is the central nervous system in experimental animals, and methylmercury is a teratogen in experimental animals and humans (ACGIH (7th, 2001)). As above, because the toxicity information of "methylmercury" is thought to be applicable for the classification in this hazard class as mentioned at the front, the substance was classified in "Category 1A" in this hazard class, and "effects on or via lactation" was added.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
8	Specific target organ toxicity - Single exposure	Category 1 (nervous system)	Danger	H370	P308+P311 P260 P264 P270 P321 P405 P501	In acute inhalation exposure to alkyl mercury compounds in humans, neurological effects such as numbness and tingling of limbs, unsteady gait, and walking difficulty were observed (ATSDR (1999)). Also for this substance, as effects in humans, there is a case of a female chemist who inadvertently spilled several drops (estimated as 0.44 mL) of dimethylmercury onto the disposable gloves she wore and showed disturbance in balance, gait, and speech by exposure via penetrating gloves (in addition to dermal exposure, inhalation exposure is suggested from the property of this substance). Even after hospitalization and treatment, she became comatose 175 days after exposure and died after 298 days (ATSDR (1999)). Therefore, the substance was classified in Category 1 (nervous system).	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
9	Specific target organ toxicity - Repeated exposure	Category 1 (nervous system, kidney)	Danger	H372	P260 P264 P270 P314 P501	As effects in humans, it is reported that after 2-week dermal exposure, a 23-year-old laboratory worker showed gingival pain, salivation, numbness of hands/feet/tongue, deafness, weak sight, slow answers to questions with an inarticulate voice, throat pain in swallowing, unable to speak, and a death from pneumonia (at least 12 months after exposure), and a 30-year-old chemist who synthesized 6 kg dimethylmercury within 3 months developed constriction of the visual field and symptoms of related to disturbance to the cerebellum and cerebral cortex (paralysis and deafness) (GESTIS (Access on August 2015)). Furthermore, it is not this substance, but it is written in ACGIH that major target organs of alkyl mercury compounds are the central and peripheral nervous systems and the kidney (ACGIH (7th, 2001)), and it is reported in ATSDR that irreversible disturbance in the brain and kidney occurred in a part of people who ate fish contaminated with a large amount of methylmercury and in a part of people who ate seeds treated with methylmercury or other organic mercury compounds (ATSDR (1999)). From the above, it is thought that the nervous system is the main target organ, and the kidney is also a target organ. Therefore, the substance was classified in Category 1 (nervous system, kidney).	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
10	Aspiration hazard	Classification not possible	- -	-	-	Due to lack of data, the classification is not possible.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))

ENVIRONMENTAL HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification	Classification year (FY)	GHS Classification Guidance for the Japanese Government
11	Hazardous to the aquatic environment Short term (Acute)	Classification not possible	- -	-	-	No data.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
11	Hazardous to the aquatic environment Long term (Chronic)	Classification not possible	- -	-	-	No data.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
12	Hazardous to the ozone layer	Classification not possible	- -	-	-	No data.	FY2015	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))

NOTE:

GHS Classification Result by the Japanese Government is intended to provide a reference for preparing a GHS label or SDS for users. To include the same classification result in a label or SDS for Japan is NOT mandatory.
Users can cite or copy this classification result when preparing a GHS label or SDS. Please be aware, however, that the responsibility for a label or SDS prepared by citing or copying this classification result lies with users.
This GHS classification was conducted based on the information sources and the guidance for classification and judgement which are described in the GHS Classification Guidance for the Japanese Government etc. Using other literature, test results etc. as evidence and including different content from this classification result in a label or SDS are allowed.
Hazard statement and precautionary statement will show by hovering the mouse cursor over a code in the column of "Hazard statement" and "Precautionary statement," respectively. In the excel file, both the codes and statements are provided.
A blank or "-" in the column of "Classification" denotes that a classification for the hazard class was not conducted in the year.
An asterisk “*” in the column of “Classification” denotes that “Not classified (or No applicable)” and/or “Classification not possible” is applicable. Details are described in the column of “Rationale for the classification”. If no English translation is available for “Rationale for the classification,” please refer to the Japanese version of the results.

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