GHS Classification Result (Revision of the past classification result)

Chemical Name:Isoprene
CAS:78-79-5

Result:
ID: 21B3081
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 - - - - 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 Category 1 Danger H224: Extremely flammable liquid and vapour P303+P361+P353: IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower.
P370+P378: In case of fire: Use ... for extinction.
P403+P235: Store in a well-ventilated place. Keep cool.
P210: Keep away from heat/sparks/open flames/hot surfaces. - No smoking.
P233: Keep container tightly closed.
P240: Ground/bond container and receiving equipment.
P241: Use explosion-proof electrical/ventilating/lighting/.../equipment.
P242: Use only non-sparking tools.
P243: Take precautionary measures against static discharge.
P280: Wear protective gloves/protective clothing/eye protection/face protection.
P501: Dispose of contents/container to ...
Classified into Category 1 since flash point -54 degC (closed-cup) (ICSC (2004)) is <23 degC and initial boiling point 34 degC is <=35 degC. The substance containing stabilizers is classified into Class 3, PG I in UNRTDG (UN1218).
7 Flammable solids Not applicable - - - - Liquid (GHS definition)
8 Self-reactive substances and mixtures Type G - - - - Classified into Type G since the usually distributed substance containing stabilizers is classified into Class 3, PG I in UNRTDG (UN1218) though there are chemical groups (unsaturated C=C)) associated with self-reactive properties present in the molecules.
9 Pyrophoric liquids Not classified - - - - Classified into Not classified from auto-ignition point 220 degC (ICSC (2004)).
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 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 - - - - Organic compounds containing no oxygen, fluorine or chlorine
14 Oxidizing solids Not applicable - - - - Liquid (GHS definition)
15 Organic peroxides Not applicable - - - - Organic compounds containing no bivalent -O-O- structure
16 Corrosive to metals Classification not possible - - - - Test methods applicable to liquid (low boiling point (34 degC) (ICSC (2004))) substances are not available.

HEALTH HAZARDS
Hazard class Classification Symbol Signal word Hazard statement Precautionary statement Rationale for the classification
1 Acute toxicity (Oral) Not classified - - - - Based on a LD50 value of 2,043 mg/kg for rats (SIDS (2005)), the substance was classified into "Not classified" in JIS Classification (correspond to Category 5 in GHS classification).
1 Acute toxicity (Dermal) Classification not possible - - - - Classification not possible due to lack of data. As relevant information, a LD50 value is >1 mL/kg bw (681 mg/kg bw) for rats (SIDS (2005)).
1 Acute toxicity (Inhalation: Gases) Not applicable - - - - Liquid (GHS definition)
1 Acute toxicity (Inhalation: Vapours) Not classified - - - - Based on a LC50 value of 180 mg/L/4h (64607 ppm/4h) for rats (SIDS (2005)), the substance was classified as "Not classified". Since the test concentration (63,600 ppm) was lower than 90% of saturated vapour pressure concentration (725,000 ppm), the classification criteria for gas were adopted.
1 Acute toxicity (Inhalation: Dusts and mists) Classification not possible - - - - No data available.
2 Skin corrosion/irritation Not classified - - - - Based on results of "slightly irritating" in rabbits following prolonged or repeated application and application twice a day for 5 consecutive days (SIDS (2005)), the substance was classified as "Not classified" in JIS Classification (correspond to Category 3 in GHS classification).
3 Serious eye damage/eye irritation Category 2B - Warning H320: Causes eye irritation P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P337+P313: If eye irritation persists: Get medical advice/attention.
P264: Wash ... thoroughly after handling.
Since slight irritation was found in the eyes of exposed human volunteers (Hazard Assessment Report (CERI, NITE) (2006)), the substance was classified into Category 2B.
4 Respiratory sensitization Classification not possible - - - - No data available.
4 Skin sensitization Classification not possible - - - - No data available.
5 Germ cell mutagenicity Category 2 Warning H341: Suspected of causing genetic defects P308+P313: IF exposed or concerned: Get medical advice/attention.
P201: Obtain special instructions before use.
P202: Do not handle until all safety precautions have been read and understood.
P281: Use personal protective equipment as required.
P405: Store locked up.
P501: Dispose of contents/container to ...
Based on positive results in a peripheral erythrocyte micronucleus test by inhalation exposure to rats for 2, 13, 40 and 80 weeks (in vivo somatic cell mutagenicity test) (Initial Risk Assessment Report (NITE, CERI, NEDO) (2005), NTP DB (2009)), the substance was classified into Category 2. As relevant information, negative results are reported from in vivo tests including a mouse pulmonary fibroblast micronucleus test and a mouse bone marrow chromosomal aberration test (Initial Risk Assessment Report (NITE, CERI, NEDO) (2005)). From in vitro mutagenicity tests, there are reports of a negative Ames test and a negative CHO cell chromosomal aberration test (Initial Risk Assessment Report (NITE, CERI, NEDO) (2005), NTP DB (2009)).
6 Carcinogenicity Category 2 Warning H351: Suspected of causing cancer P308+P313: IF exposed or concerned: Get medical advice/attention.
P201: Obtain special instructions before use.
P202: Do not handle until all safety precautions have been read and understood.
P281: Use personal protective equipment as required.
P405: Store locked up.
P501: Dispose of contents/container to ...
Based on the classifications of "2B" in IARC (IARC (1999)), "R" in NTP (NTP (2005)) and "2B" in Japan Society For Occupational Health (JSOH), the substance was classified into Category 2. In a 105-week inhalation test in rats, increases in the incidences of mammary gland fibroadenoma, mammary gland carcinoma, renal tubule adenoma and interstitial cell adenoma were observed (NTP TR486 (1999)). In a 80-week inhalation test in mice, increases in the incidence of tumours were found in the liver, kidney, spleen and Harderian gland (IARC vol. 71 (1999)).
7 Reproductive toxicity Classification not possible - - - - In developmental toxicity tests in rats and mice exposed by inhalation during the organogenesis period, there were no fetal developmental toxicity including teratogenicity (SIDS (2005)). Classification was not possible because of lack of sufficient data for effects on parental sexual function and fertility due to exposure prior to mating.
8 Specific target organ toxicity - Single exposure Category 3 (Narcotic effects, Respiratory tract irritation) Warning H336: May cause drowsiness or dizziness (narcotic effects, respiratory tract irritation) P304+P340: IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing.
P403+P233: Store in a well-ventilated place. Keep container tightly closed.
P261: Avoid breathing dust/fume/gas/mist/vapours/spray.
P271: Use only outdoors or in a well-ventilated area.
P312: Call a POISON CENTER or doctor/physician if you feel unwell.
P405: Store locked up.
P501: Dispose of contents/container to ...
In a human sensory evaluation, mild irritation in the upper respiratory tract mucosa, larynx and throat were observed at a substance concentration of 160 mg/m3 (58 ppm) (Initial Risk Assessment Report (NITE, CERI, NEDO) (2005)). Human volunteers experienced irritation of the upper respiratory after exposure to a 60 ppm concentration of the substance (NTP TR486 (1999)). Based on the data, the substance was classified into Category 3 (respiratory tract irritation). The substance affects the central nervous system, and induces respiratory dysfunction and lowering of consciousness. In an inhalation exposure test in mice, loss of righting reflex and CNS depression were observed at high doses (97.5 - 125.3 mg/L) which were less than a lethal dose (PATTY (5th, 2001)). Based on the data, the substance was classified into Category 3 (narcotic effects).
9 Specific target organ toxicity - Repeated exposure Category 1 (nervous system, upper respiratory tract) Danger H372: Cause damage to organs through prolonged or repeated exposure (nervous system, upper respiratory tract) P260: Do not breathe dust/fume/gas/mist/vapours/spray.
P264: Wash ... thoroughly after handling.
P270: Do not eat, drink or smoke when using this product.
P314: Get medical advice/attention if you feel unwell.
P501: Dispose of contents/container to ...
In a 13-week inhalation test with mice, increased incidences of macrocytic anemia, hyperplasia of the forestomach, degeneration of the olfactory epithelium and cytoplasmic degeneration of the liver were observed (SIDS (2005)). In a 26-week inhalation test with mice (dose levels: 0.195 - 19.5 mg/L), increased incidences of hindlimb paralysis, spinal cord degeneration, degeneration of the olfactory epithelium, epithelial hyperplasia of the forestomach, and macrocytic anemia were observed. Grip strength of the hindlimb in the 220 ppm (0.613 mg/L) and higher concentration exposure groups was significantly lower than that in the control group (SIDS (2005)). After 26 week of recovery, the incidence of degeneration of the spinal cord was significantly increased in all treatment groups (SIDS (2005)). Since degeneration of the spinal cord is considered to be a cause of hindlimb paralysis and this effect occurred at dose levels within the guidance value range for Category 1, the substance was classified into Category 1 (nervous system). The significant increase in the incidence of degeneration of the olfactory epithelium was observed in the 220 ppm (0.613 mg/L) and higher treatment groups after 26 weeks of recovery. In isoprene rubber production workers, atrophic processes in the upper respiratory tract, catarrhal inflammation, and degeneration of the olfactory tract were noted (IARC vol. 71 (1991)). Based on these data, the substance was classified into Category 1 (upper respiratory tract). Since hepatocyte degeneration and hyperplasia of the forestomach were observed at dose levels exceeding the guidance value range for Category 2, the data were not used as the basis of classification. In a 2-week inhalation test in mice, a decrease in erythrocyte count and hemoglobin concentration was noted at dose levels of 438 ppm (90-day equivalence: 0.2 mg/L) (Hazard Assessment Report (CERI, NITE) (2006)). However, this data was not used as the basis of classification because of lack of other data for the effect on blood system.
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 2 - - H401: Toxic to aquatic life P273: Avoid release to the environment.
P501: Dispose of contents/container to ...
Classified into Category 2 from its 48h-EC50 = 3.2 mg/L for Crustacea (Daphnia magna) (Test for the Ecological Effect of Chemical Substances (Ministry of the Environment), 2000).
11 Hazardous to the aquatic environment (Long-term) Category 2 - H411: 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 2 since its acute toxicity is Category 2 and it is not rapidly degradable (BOD degradation rate: 2% (Biodegradation and Bioconcentration of Existing Chemical Substances under the Chemical Substances Control Law, 1988)).
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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