Methocarbamol SDS/MSDS (Safety Data Sheet)

3.1 Substances
Product name: Methocarbamol
CAS Number: 532-03-6
PubChem CID: 4107
Molecular formula: C11H15NO5
Molecular weight: 241.24 g/mol
IUPAC name: [2-hydroxy-3-(2-methoxyphenoxy)propyl] carbamate

3.2 Mixtures
Not applicable (pure substance).

4.1 Description of first aid measures
Inhalation: Move to fresh air. Keep at rest in a position comfortable for breathing. Seek medical attention if symptoms persist.
Skin contact: Wash with plenty of soap and water. Remove contaminated clothing. Seek medical attention if irritation develops.
Eye contact: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing. Seek medical attention.
Ingestion: Rinse mouth. Do NOT induce vomiting unless directed by medical personnel. Seek medical attention.

4.2 Most important symptoms and effects, both acute and delayed
See Section 11 (Toxicological Information).

4.3 Indication of any immediate medical attention and special treatment needed
Treat symptomatically. Contact a poison control center or physician for severe exposure.

5.1 Extinguishing media
Suitable: Water spray, dry chemical, carbon dioxide (CO2), alcohol-resistant foam.
Unsuitable: None known.

5.2 Specific hazards arising from the substance or mixture
Combustible. Heating may produce toxic fumes.

5.3 Advice for firefighters
Wear self-contained breathing apparatus (SCBA) and full protective clothing.
Fight fire from upwind. Cool containers with water spray until fire is extinguished.

6.1 Personal precautions, protective equipment and emergency procedures
Wear appropriate personal protective equipment (see Section 8).
Avoid breathing dust/vapor. Ensure adequate ventilation.
Evacuate personnel to safe areas. Keep people away from and upwind of spill.

6.2 Environmental precautions
Prevent product from entering drains, waterways, or soil.
Contain spill with inert absorbent material.

6.3 Methods and materials for containment and cleaning up
SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

7.1 Precautions for safe handling
Methocarbamol tablets should be stored in tight containers at a temperature less than 40 °C, preferably between 15-30 °C. methocarbamol injection should be stored at 15-30 °C; freezing of the injection should be avoided.
IV infusion solutions prepared from methocarbamol injection should not be refrigerated since precipitation and haze formation may occur. At 4 °C, precipitation and haze occur at methocarbamol concentrations of about 15 mg/mL or higher when the drug is diluted in 5% dextrose, 5% dextrose and 0.45% sodium chloride, or 0.9% sodium chloride injection and also occasionally occur at lower concentrations.

7.2 Conditions for safe storage, including any incompatibilities
Methocarbamol tablets should be stored in tight containers at a temperature less than 40 °C, preferably between 15-30 °C. methocarbamol injection should be stored at 15-30 °C; freezing of the injection should be avoided.
IV infusion solutions prepared from methocarbamol injection should not be refrigerated since precipitation and haze formation may occur. At 4 °C, precipitation and haze occur at methocarbamol concentrations of about 15 mg/mL or higher when the drug is diluted in 5% dextrose, 5% dextrose and 0.45% sodium chloride, or 0.9% sodium chloride injection and also occasionally occur at lower concentrations.
Store away from incompatible materials (see Section 10).
[Note: Specific storage temperature not available in public databases. Refer to supplier Certificate of Analysis (COA) for exact storage conditions.]

9.1 Information on basic physical and chemical properties
a) Appearance: Solid
b) Odor: No data available
c) Odor threshold: No data available
d) pH: No data available
e) Melting point/freezing point: 92-94 °C
f) Initial boiling point and boiling range: No data available
g) Flash point: No data available
h) Evaporation rate: No data available
i) Flammability (solid, gas): No data available
j) Upper/lower flammability or explosive limits: No data available
k) Vapor pressure: No data available
l) Vapor density: No data available
m) Relative density: No data available
n) Water solubility: 2.5g/100mL
o) Partition coefficient: n-octanol/water: Log P (n-octanol/water): 0.6
p) Auto-ignition temperature: No data available
q) Decomposition temperature: No data available
r) Viscosity: No data available
s) Explosive properties: No data available
t) Oxidizing properties: No data available

9.2 Other information
Topological Polar Surface Area (TPSA): 91 Ų
Complexity: 236

11.1 Information on toxicological effects
Acute toxicity:
No acute toxicity data available.
Skin corrosion/irritation:
No data available.
Serious eye damage/eye irritation:
No data available.
Respiratory or skin sensitization:
May cause allergy or asthma symptoms or breathing difficulties if inhaled (H334).
Germ cell mutagenicity:
No data available.
Carcinogenicity:
No data available.
Reproductive toxicity:
No data available.
Specific target organ toxicity (single exposure):
No data available.
Specific target organ toxicity (repeated exposure):
No data available.
Aspiration hazard:
No data available.

11.2 Additional information
No additional toxicological information available.

12.1 Toxicity
Methocarbamol's production and use as a muscle relaxant may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 3.4X10-7 mm Hg at 25 °C indicates methocarbamol will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase methocarbamol will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 8.5 hours. Particulate-phase methocarbamol will be removed from the atmosphere by wet or dry deposition. Methocarbamol does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, methocarbamol is expected to have high mobility based upon an estimated Koc of 51. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 6.5X10-16 atm-cu m/mole. Methocarbamol is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation of methcarbamol in soil and water is not expected to be an important fate process based on the results of a Japanese MITI test where methocarbamol reached 4% of its theoretical BOD in activated sludge after 4 weeks. If released into water, methocarbamol is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfa

12.2 Persistence and degradability
No data available.

12.3 Bioaccumulative potential
Log P (n-octanol/water): 0.6
Low potential for bioaccumulation (Log P < 3).

12.4 Mobility in soil
No data available.

12.5 Results of PBT and vPvB assessment
PBT/vPvB assessment not available.

12.6 Other adverse effects
No other adverse ecological effects identified.

13.1 Waste treatment methods
Waste Treatment Methods: Waste material must be disposed of in accordance with national and local regulations. Leave chemicals in original containers and do not mix with other waste. Handle uncleaned containers in the same manner as the product itself.

14.1 UN number
Not regulated as dangerous goods (research quantities typically exempt).

14.2 UN proper shipping name
Not subject to transport regulations (small quantities for research use).

14.3 Transport hazard class(es)
Not classified as dangerous goods for transport (research quantities).

14.4 Packing group
Not applicable (not regulated as dangerous goods in typical research quantities).

14.5 Environmental hazards
Marine pollutant: No (not classified as environmentally hazardous per GHS).

14.6 Special precautions for user
Transport in original packaging. Ensure containers are tightly sealed.
For bulk or commercial quantities, consult applicable transport regulations (DOT, IATA, IMDG).

14.7 Transport in bulk according to Annex II of MARPOL 73/78 and the IBC Code
Not applicable.

15.1 Safety, health and environmental regulations/legislation specific for the substance or mixture
US EPA / TSCA: Subject to EPA TSCA regulations
EU ECHA / REACH: Not available in public databases.

SARA 302 Components:
No chemicals in this material are subject to the reporting requirements of SARA Title III, Section 302.
SARA 313 Components:
This material does not contain any chemical components with known CAS numbers that exceed the threshold (De Minimis) reporting levels established by SARA Title III, Section 313.
SARA 311/312 Hazards:
Acute (short-term) health hazard

Massachusetts Right To Know Components:
This material contains components subject to the Massachusetts Right to Know Act. See Section 2 for hazard classification.
Pennsylvania Right To Know Components:
This material contains components subject to the Pennsylvania Right to Know Act. See Section 2 for hazard classification.
New Jersey Right To Know Components:
This material contains components subject to the New Jersey Right to Know Act. See Section 2 for hazard classification.

California Prop. 65 Components:
This product does not contain any chemicals known to the State of California to cause cancer, birth defects, or any other reproductive harm.

Other regulatory listings:
- FDA Requirements: The Approved Drug Products with Therapeutic Equivalence Evaluations List identifies currently marketed prescription drug products, incl methocarbamol, approved on the basis of safety and effectiveness by FDA under sections 505 of the Federal Food, Drug, and Cosmetic Act.
The Generic Animal Drug an

15.2 Chemical safety assessment
A chemical safety assessment has not been carried out for this substance.
For research-use-only compounds, no CSA is required under REACH Annex I.

Revision Date: 2026/09/08
Further Information: The information provided is believed to be correct but is not exhaustive and should be used only as a guideline based on current knowledge. It does not represent a guarantee of the properties of the product. Selleck Chemicals Corporation and its Affiliates shall not be held liable for any damage resulting from handling or contact with the product.