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GHS Classification Results by the Japanese Government

GENERAL INFORMATION

Item	Information
CAS RN	10024-97-2
Chemical Name	Dinitrogen oxide; Nitrous oxide
Substance ID	R01-B-039
Classification year (FY)	FY2019
Ministry who conducted the classification	Ministry of Health, Labour and Welfare (MHLW)/Ministry of the Environment (MOE)
New/Revised	Revised
Classification result in other fiscal year	FY2006
Download of Excel format	Excel file

REFERENCE INFORMATION

Item	Information
Guidance used for the classification (External link)	GHS Classification Guidance for the Japanese Government (FY2013 revised edition (Ver. 1.1))
UN GHS document (External link)	UN GHS document
Definitions/Abbreviations (Excel file)	Definitions/Abbreviations
Model Label by MHLW (External link)
Model SDS by MHLW (External link)	MHLW Website (in Japanese Only)
OECD/eChemPortal (External link)	eChemPortal

PHYSICAL HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification
1	Explosives	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
2	Flammable gases	*	- -	-	-	It was classified as "Not classified" from information that it is a non-flammable gas (Hommel (1991)).
3	Aerosols	*	- -	-	-	Not aerosol products. It was classified as "Not classified (Not applicable)."
4	Oxidizing gases	Category 1	Danger	H270	P370+P376 P220 P244 P403	It was classified in Category 1 because it is classified in Division 2.2, Subsidiary Risk 5.1 in UNRTDG (UN 2201).
5	Gases under pressure	High pressure liquefied gas	Warning	-	-	It was classified as high-pressure liquefied gases from a critical temperature of 36.65 deg C (Japanese Pharmacopoeia (2018)).
6	Flammable liquids	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
7	Flammable solids	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
8	Self-reactive substances and mixtures	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
9	Pyrophoric liquids	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
10	Pyrophoric solids	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
11	Self-heating substances and mixtures	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
12	Substances and mixtures which, in contact with water, emit flammable gases	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
13	Oxidizing liquids	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
14	Oxidizing solids	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
15	Organic peroxides	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."
16	Corrosive to metals	*	- -	-	-	Classification is not possible because test methods applicable to gas substances are not available.
17	Desensitized explosives	*	- -	-	-	Gas (GHS definition). It was classified as "Not classified (Not applicable)."

HEALTH HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification
1	Acute toxicity (Oral)	*	- -	-	-	[Rationale for the Classification] Gas (GHS definition). It was classified as "Not classified (Not applicable)."
1	Acute toxicity (Dermal)	*	- -	-	-	[Rationale for the Classification] Gas (GHS definition). It was classified as "Not classified (Not applicable)."
1	Acute toxicity (Inhalation: Gases)	*	- -	-	-	[Rationale for the Classification] Classification not possible due to lack of data.
1	Acute toxicity (Inhalation: Vapours)	*	- -	-	-	[Rationale for the Classification] Gas (GHS definition). It was classified as "Not classified (Not applicable)."
1	Acute toxicity (Inhalation: Dusts and mists)	*	- -	-	-	[Rationale for the Classification] Gas (GHS definition). It was classified as "Not classified (Not applicable)."
2	Skin corrosion/irritation	*	- -	-	-	[Rationale for the Classification] Classification not possible due to lack of data.
3	Serious eye damage/eye irritation	*	- -	-	-	[Rationale for the Classification] Classification not possible due to lack of data.
4	Respiratory sensitization	*	- -	-	-	[Rationale for the Classification] Classification not possible due to lack of data.
4	Skin sensitization	*	- -	-	-	[Rationale for the Classification] Classification not possible due to lack of data.
5	Germ cell mutagenicity	*	- -	-	-	[Rationale for the Classification] There are no in vivo data on this substance alone. However, negative results were obtained in in vitro tests of multiple indicators. Therefore, based on expert judgments, it was classified as "Not classified." [Evidence Data] (1) As for in vivo, there are no data on studies conducted with this substance alone. (2) As for in vitro, there are negative results in a bacterial reverse mutation test, an HPRT test and a micronucleus test with cultured mammalian cells (DFGOT vol.9 (1998), ACGIH (7th, 2001)). [Reference Data, etc.] (3) As for in vivo, in a test in which rats were concurrently exposed to this substance and halothane (CAS RN 151-67-7), chromosomal aberrations in the bone marrow cells and spermatogonia were reported. However, halothane alone also has clastogenic effects so it is not clear whether this substance alone has clastogenic effects (DFGOT vol.9 (1998)). (4) In epidemiological and occupational exposure data where exposure to this substance was clear, neither increased SCE nor chromosomal aberrations were observed in lymphocytes in workers (DFGOT vol.9 (1998)).
6	Carcinogenicity	*	- -	-	-	[Rationale for the Classification] Based on classification results by other organizations in (1), it was classified as "Classification not possible" in accordance with the GHS Classification Guidance for the Japanese Government. [Evidence Data] (1) As for classification results by domestic and international organizations, it was classified as A4 by ACGIH (ACGIH (7th, 2001)).
7	Reproductive toxicity	Category 1A	Danger	H360	P308+P313 P201 P202 P280 P405 P501	[Rationale for the Classification] Based on (1)-(3), since increases in spontaneous abortions were observed in exposed humans, it was classified in Category 1A. [Evidence Data] (1) In female workers who were exposed to waste anesthetic gas, increases in spontaneous abortions were reported (ACGIH (7th, 2001), DFGOT vol.9 (1998), IPCS, PIM 381 (1991)). (2) Also, in female dentists and their assistants exposed to anesthetic gas in dental clinics, increases in spontaneous abortions were reported (ACGIH (7th, 2001)). (3) There is a report that increases in congenital abnormalities were observed in children of women who were exposed during pregnancy, but it was not proven (ACGIH (7th, 2001), DFGOT vol.9 (1998), IPCS, PIM 381 (1991)). [Reference Data, etc.] (4) In a developmental toxicity test with pregnant rats exposed by inhalation, after continuous exposure to high concentrations (50,000-75,000 ppm) for 24 hours, an increased resorption rate, visceral and skeletal anomalies were reported, however, for intermittent exposures less than 24 hours/day, effects were less pronounced or not detectable (DFGOT vol.9 (1998)).
8	Specific target organ toxicity - Single exposure	Category 3 (Narcotic effects)	Warning	H336	P304+P340 P403+P233 P261 P271 P312 P405 P501	[Rationale for the Classification] Based on (1) and (2), it was classified in Category 3 (narcotic effects). [Evidence Data] (1) It was described that it showed analgesic effects at or above 300,000 ppm and anesthetic effects at or above 800,000 ppm in inhalation exposure (DFGOT vol.9 (1998)). (2) In the medical field, this substance has been used for a long time as an inhalation anesthetic in Japan and internationally and is listed in the Japanese Pharmacopoeia (Risk Assessment Report (Food Additives) (Food Safety Commission of Japan, 2004)).
9	Specific target organ toxicity - Repeated exposure	Category 1 (nervous system, hematopoietic system)	Danger	H372	P260 P264 P270 P314 P501	[Rationale for the Classification] Based on (1)-(3), this substance was considered to affect the nervous system and hematopoietic system in humans. Therefore, it was classified in Category 1 (nervous system, hematopoietic system). By reviewing the information sources, the classification result was changed from the previous classification. [Evidence Data] (1) Chronic exposure to high concentrations of this substance may cause megaloblastic bone marrow depression and neurological symptoms (IPCS, PIM 381 (1991), HSDB (Access on July 2019)). (2) Reversible bone marrow depression with aplastic anemia was observed in tetanus patients exposed to 500,000 ppm of this substance as a sedative for 23 days (DFGOT vol.9 (1998)). (3) In dentists heavily exposed to this substance (greater than 3000 hours within the prior 10 years), neurologic symptoms (numbness, tingling, and weakness) were observed (ACGIH (7th, 2001)). [Reference Data, etc.] (4) There is a report that hepatic and renal disease rates were higher for dentists and dental assistants exposed to this substance. On the other hand, there is also a report that tests for hepatic and hematological functions, performed on operating room personnel, ward nurses, and technicians and physicians on radiology services, showed no significant differences between the groups exposed to the anesthetic gases containing this substance and the control group (ACGIH (7th, 2001), Cohen et al., 1980, De Zotti et al., 1983).
10	Aspiration hazard	*	- -	-	-	[Rationale for the Classification] Gas (GHS definition)

ENVIRONMENTAL HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification
11	Hazardous to the aquatic environment Short term (Acute)	Classification not possible	- -	-	-	Classification not possible due to lack of data.
11	Hazardous to the aquatic environment Long term (Chronic)	Classification not possible	- -	-	-	Classification not possible due to lack of data.
12	Hazardous to the ozone layer	Classification not possible	- -	-	-	Classification not possible due to lack of data.

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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