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GHS Classification Result

GENERAL INFORMATION

Item	Information
CAS RN	56-38-2
Chemical Name	Parathion
Substance ID	H28-B-027, C-038B
Classification year (FY)	FY2016
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)	MHLW Website (in Japanese Only)
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	Classification not possible	- -	-	-	There is a chemical group associated with explosive properties (N-O group) present in the molecule, but the classification is not possible due to no data.
2	Flammable gases (including chemically unstable gases)	Not applicable	- -	-	-	Liquid (GHS definition)
3	Aerosols	Not applicable	- -	-	-	Not aerosol products.
4	Oxidizing gases	Not applicable	- -	-	-	Liquid (GHS definition)
5	Gases under pressure	Not applicable	- -	-	-	Liquid (GHS definition)
6	Flammable liquids	Not classified	- -	-	-	A flash point is 120 deg C (ICSC (2004)).
7	Flammable solids	Not applicable	- -	-	-	Liquid (GHS definition)
8	Self-reactive substances and mixtures	Classification not possible	- -	-	-	There is a chemical group associated with explosive properties (N-O group) present in the molecule, but the classification is not possible due to no data.
9	Pyrophoric liquids	Classification not possible	- -	-	-	No data available.
10	Pyrophoric solids	Not applicable	- -	-	-	Liquid (GHS definition)
11	Self-heating substances and mixtures	Classification not possible	- -	-	-	Test methods applicable to liquid substances are not available.
12	Substances and mixtures which, in contact with water, emit flammable gases	Not classified	- -	-	-	It is estimated that it does not react vigorously with water due to the water solubility result measured (0.002 g/100 mL (25 deg C) (ICSC (2004))).
13	Oxidizing liquids	Classification not possible	- -	-	-	The substance is an organic compound containing oxygen, but the classification is not possible due to no data.
14	Oxidizing solids	Not applicable	- -	-	-	Liquid (GHS definition)
15	Organic peroxides	Not applicable	- -	-	-	Organic compounds containing no bivalent -O-O- structure in the molecule
16	Corrosive to metals	Classification not possible	- -	-	-	No data available.

HEALTH HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification
1	Acute toxicity (Oral)	Category 2	Danger	H300	P301+P310 P264 P270 P321 P330 P405 P501	There are reports of six LD50 values for rats: 2, 2.6, 6.85, 7, 13.7 and 22 mg/kg. Since two values correspond to Category 1 (JMPR (1995)) and 4 values correspond to Category 2 (JMPR (1995)), this substance was classified in Category 2, under which the greatest number of reports fall. Additionally, based on expert judgment, the LD50 values in JMPR were preferentially adopted as the information source for this substance.
1	Acute toxicity (Dermal)	Category 2	Danger	H310	P302+P352 P361+P364 P262 P264 P270 P280 P310 P321 P405 P501	Based on the report of 73 mg/kg (males and female) as the LD50 value for rats (JMPR (1995)), this substance was classified in Category 2. Following the revision of the GHS Classification Guidance for the Japanese Government, the category was revised. Additionally, based on expert judgment, the LD50 value in JMPR was preferentially adopted as the information source for this substance.
1	Acute toxicity (Inhalation: Gases)	Not applicable	- -	-	-	Liquid (GHS definition)
1	Acute toxicity (Inhalation: Vapours)	Classification not possible	- -	-	-	Classification not possible due to lack of data.
1	Acute toxicity (Inhalation: Dusts and mists)	Category 1	Danger	H330	P304+P340 P403+P233 P260 P271 P284 P310 P320 P405 P501	There are reports of five LC 50 values for rats (4 hours), which are 0.03 mg/L (males and females) (JMPR (1995)), 32- 84 mg/m3 (gender unspecified) (ACGIH (7th, 2003)), 84 mg/m3 (males) (ATSDR (2014)), 24 mg/L (females) (JMPR (1995)), and 77 - 91 mg/L (males) (JMPR (1995)). One case corresponds to Category 1, one case from to Category 1 to Category 2, one case to Category 2, and two cases to "Not classified." This substance was classified in Category 1 because the category with higher hazard was adopted. Besides, because the LC50 values are higher than the saturated vapor pressure concentration (0.00897 ppm (0.00011 mg/L)), the reference value of mist was applied. Following the revision of the GHS Classification Guidance for the Japanese Government, the category was revised. Additionally, based on expert judgment, the LD50 values in JMPR, ACGIH and ATSDR were preferentially adopted as the information sources for this substance.
2	Skin corrosion/irritation	Not classified	- -	-	-	In two skin irritation tests using rabbits, very slight to slight irritation (erythema, edema) was observed but resolved after 72 hours (JMPR (1995)), therefore, this substance was classified as "Not classified" (Category 3 in UN GHS classification).
3	Serious eye damage/eye irritation	Category 2B	- Warning	H320	P305+P351+P338 P337+P313 P264	Based on the report (JMPR (1995)) that irritation was observed in a test in which this substance was applied to the eyes of rabbits, it was classified in Category 2B.
4	Respiratory sensitization	Classification not possible	- -	-	-	Classification not possible due to lack of data.
4	Skin sensitization	Classification not possible	- -	-	-	Classification not possible due to lack of data. Additionally, there is a report that sensitization was not observed in a maximization test using guinea pigs (Magnusson-Kligman method) (ACGIH (7th, 2016), JMPR (1995)); however, the details such as the test method are unknown. Therefore, it was judged as insufficient data to be used for classification.
5	Germ cell mutagenicity	Classification not possible	- -	-	-	The substance was classified as "Classification not possible," it was not possible to classify a substance as "Not classified" according to the revised GHS classification guidance for the Japanese Government. As for in vivo tests, it was negative in all of the following: mouse dominant lethal tests, a chromosomal aberration test using mouse spermatogonial cells, micronucleus tests and a chromosome aberration test using mouse bone marrow cells (JMPR (1995), ATSDR (2014)). As for in vitro tests, they were negative in all of the following: bacterial reverse mutation tests and a gene mutation test, a chromosomal aberration test, and a sister chromatid exchange test using cultured mammalian cells (JMPR (1995), ATSDR (2014)).
6	Carcinogenicity	Category 2	Warning	H351	P308+P313 P201 P202 P280 P405 P501	There was no information on humans. As for experimental animals, in studies in rats dosed by feeding for 46 or 67 weeks, adrenal gland cortical adenomas/carcinomas in males and females (ACGIH (7th, 2003), IRIS (1988)), and an increasing trend of thyroid follicular adenomas and pancreatic islet-cell carcinomas in males (IRIS (1988)) were observed. Based on this, the EPA classified this substance in Group C (possible human carcinogen: equivalent to Category 2) (IRIS (1988)). On the other hand, IARC concluded that the carcinogenicity of this substance in experimental animals could not be evaluated, because of the short duration of treatment and because no increases were seen in tumor incidence associated with administration in other feeding studies in rats or mice (IARC 30 (1983)). Citing this, ACGIH classified this substance in A4 (ACGIH (7th, 2003)). However, IARC concluded that evidence of carcinogenicity in experimental animals of this substance was sufficient in the latest carcinogenicity assessment and changed the classification to Group 2B (IARC 112 (in prep., Access on June 2015)). Taking account of the background of the classifications by other organizations for this substance, this substance was classified in Category 2 for this hazard class.
7	Reproductive toxicity	Category 2	Warning	H361	P308+P313 P201 P202 P280 P405 P501	In three reproductive toxicity tests by the oral route (feeding) using rats, this substance was administered at up to doses at which tremors in F0 and F1 maternal animals were seen in one study and reduced plasma, erythrocyte and brain cholinesterase activities were observed in the F0 and F1 parent animals in another study, but only slight effects (lower body weights during nursing or weaning) were observed in the pups (JMPR (1995), ACGIH (7th, 2003)). However, in the third study, no toxicological findings were observed in the parent animals at up to 20 ppm, but a reduced number of pregnant animals (3/6 cases) at 20 ppm and high postnatal mortality of F1 neonates at 10 and 20 ppm were observed (Barnes & Denz (1951), IARC 30 (1983), ACGIH (7th, 2003)). On the other hand, in developmental toxicity studies using pregnant rats or pregnant rabbits dosed by gavage during the organogenesis period, both rats and rabbits had no significant toxicological findings in the fetuses even at high doses at which deaths and suppressed body weight gain occurred (JMPR (1995), ACGIH (7th, 2003)). As described above, among the three reproductive toxicity studies by feeding in rats, in one study a decreased fertility index and an increased postnatal mortality rate in the pups were observed at a dose at which no symptoms of toxicity developed in the parent animals. However, in the other two studies only slight effects were seen in the pups when the effects of general toxicity were seen in the parent animals. Therefore, it was judged to be appropriate to classify this substance in Category 2 for this hazard class.
8	Specific target organ toxicity - Single exposure	Category 1 (nervous system)	Danger	H370	P308+P311 P260 P264 P270 P321 P405 P501	Acute poisoning of this substance is due to inhibition of acetylcholinesterase at the nerve endings. In humans, initial symptoms such as headache, dizziness, nausea, and abdominal pain occur, followed by miosis, contractions, lacrimation, salivation, hyperactive bowels, blurred vision and ocular pain. Furthermore, losses of reflexes and sphincter control, convulsions, and coma occur, leading to death, which is mainly due to respiratory failure (IARC 30 (1983), ACGIH (7th, 2003)). It is reported that some of the humans who recovered from acute poisoning symptoms had what is called an "intermediate syndrome" such as respiratory paresis, severe nystagmus, weakness in the proximal limb muscles, and depressed tendon reflexes that began about two days after recovery, and these effects lasted for approximately 3 weeks (ACGIH (7th, 2003)). In laboratory animals, decreased cholinesterase activity, tremors, and ataxia were reported at doses equivalent to the guidance value for Category 1 in rats (ACGIH (7th, 2003)). From the above, this substance was classified in Category 1 (nervous system).
9	Specific target organ toxicity - Repeated exposure	Category 1 (nervous system, visual organs)	Danger	H372	P260 P264 P270 P314 P501	It was reported that field workers involved in spraying parathion on agricultural fields had erythrocyte cholinesterase activities ranging from 60% to 70% of the baseline (ACGIH (7th, 2003)). In experimental animals, it has been reported as follow: In a 29-day repeated dose toxicity study by feeding in mice, effects on the nervous system (tremors and decreased activity) at 100 ppm (4.8 mg/kg/day), which corresponds to Category 1, and effects on the stomach (erosion) at 200 ppm (9.7 mg/kg/day) were observed. In a 28-month repeated dose toxicity study by feeding in rats, reduced brain acetylcholinesterase activity in both sexes (males: 22% of controls, females: 18% of controls), tremors, abnormal gait, and retinal degeneration in females, and neuropathy characterized by myelin sheath degeneration in the proximal sciatic nerve, demyelination, etc. in males were seen at 50 ppm (2.5 mg/kg/day), which corresponds to Category 1. In a 2-year repeated dose toxicity study by feeding in rats, reduced erythrocyte and plasma cholinesterase activity (>20% of controls) at 8 ppm (0.04 mg/kg/day), which corresponds to Category 1, and in addition reduced brain cholinesterase activity, poor general condition, chromodacryorrhea, tremors, head tilt (the increase in symptoms was not statistically significant), structural degeneration of the retina and retinal atrophy at 32 ppm (1.6 mg/kg/day) were seen. In addition, it has been reported that depressed erythrocytes, plasma, and brain acetylcholinesterase activities were seen at doses within the range of Category 1 in a three-month repeated dose toxicity study by feeding in rats and an 18-month repeated dose toxicity study by feeding in mice (JMPR (1995)). As for the stomach, because the finding seemed to be due to irritation, it was not considered as a target organ. Therefore, this substance was classified in Category 1 (nervous system, visual organs).
10	Aspiration hazard	Classification not possible	- -	-	-	Classification not possible due to lack of data. Besides, the kinematic viscosity is calculated as 12.2 mm2/sec (25/25 degC) based on numerical data (viscosity: 15.30 mPa*s (25 degC), density (specific gravity): 1.26 (25/4 degC)) listed in HSDB (Access on May 2016).

ENVIRONMENTAL HAZARDS

Hazard class		Classification	Pictogram Signal word	Hazard statement (code)	Precautionary statement (code)	Rationale for the classification
11	Hazardous to the aquatic environment (Acute)	Category 1	Warning	H400	P273 P391 P501	From 48-hour LC50 = 0.0009 mg/L for crustacea (Gambusia affinis) (ECETOC TR91, 2003), it was classified in Category 1.
11	Hazardous to the aquatic environment (Long-term)	Category 1	Warning	H410	P273 P391 P501	If chronic toxicity data are used, then it is classified in Category 1 due to being not rapidly degradable (rapid degradability: no (SRC: BioWin V4.10)), and 21-day NOEC (lethal) = 0.000125 mg/L for crustacea (Daphnia magna) (ECETOC TR91, 2003). If acute toxicity data are used for a trophic level for which chronic toxicity data are not obtained, then it is classified in Category 1 due to being not rapidly degradable (BIOWIN), and 96-hour LC50 = 0.5 mg/L for fish (Pimephales promelas) (ECETOC TR91, 2003). It was classified in Category 1 from the above results.
12	Hazardous to the ozone layer	Classification not possible	- -	-	-	No data available.

NOTE:

* A blank or "-" in a cell of classification denotes that the classification of the hazard class was not conducted.
* Hazard_statement_and/or_Precautionary_statement will show when hovering the mouse over a code of Hazard_statement_and/or_Precautionary_statement.
Hazard_statement_and/or_Precautionary_statement are also provided in the Excel file.
* 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.
* Codes assigned to each of the hazard statements and codes for each of the precautionary statement are
based on the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) in United Nations.

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