Melatonin SDS/MSDS (Safety Data Sheet)

3.1 Substances
Product name: Melatonin
CAS Number: 73-31-4
PubChem CID: 896
Molecular formula: C13H16N2O2
Molecular weight: 232.28 g/mol
IUPAC name: N-[2-(5-methoxy-1H-indol-3-yl)ethyl]acetamide

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: 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
Handle in accordance with good industrial hygiene and safety practices.
Wear appropriate PPE (see Section 8). Avoid contact with skin, eyes, and clothing.
Wash hands thoroughly after handling. Do not eat, drink, or smoke in work area.
Avoid dust formation. Use only in a chemical fume hood or well-ventilated area.

7.2 Conditions for safe storage, including any incompatibilities
Store in a cool, dry, well-ventilated area. Keep container tightly closed.
Store away from incompatible materials (see Section 10).
Protect from light and moisture.
Recommended storage (industry convention for research compounds): -20°C for long-term storage; 2-8°C for short-term use and transport.
[Note: This is a general industry recommendation. Always verify exact storage conditions with the supplier Certificate of Analysis (COA).]

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: 116-118 °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: In water, 2 g/L at 20 °C; 5 g/L at 50 °C
o) Partition coefficient: n-octanol/water: Log P (n-octanol/water): 0.8
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): 54.1 Ų
Complexity: 270

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:
No data available.
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
Carcinogen classification:
No indication of carcinogenicity to humans (not listed by IARC).
Exposure routes:
The absorption and bioavailability of melatonin varies widely.
Signs and symptoms of exposure:
Loss of coordination, slowed reaction time, sleepiness and impaired judgment.
Data source: Hazardous Substances Data Bank (HSDB) via PubChem.

12.1 Toxicity
Melatonin's production and use in drugs and dietary supplements may result in its release to the environment through various waste streams. Melatonin is a substance found in the pineal gland of animals and humans. It occurs in many plants including feverfew, St John's wort, rice, corn, tomato and edible fruits such as cherries, bananas and grapes. If released to air, an estimated vapor pressure of 1.4X10-7 mm Hg at 25 °C indicates melatonin will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase melatonin 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 about 2 hours. Particulate-phase melatonin will be removed from the atmosphere by wet and dry deposition. Melatonin absorbs at wavelengths >290 nm and, therefore, may be susceptible to direct photolysis by sunlight. If released to soil, melatonin is expected to have low mobility based upon an estimated Koc of 904. Melatonin has pKa values of 16.51 and -0.69 and is uncharged in the entire pH-range; therefore, sorption in soil will be determined by the neutral form of melatonin. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 2.6X10-14 atm-cu m/mole. Melatonin is not expected to volatilize from dry soil surfaces based upon its vapor pressure. A strain of bacterium (Shewanella putrefaciens) isolated from an estuar

12.2 Persistence and degradability
No data available.

12.3 Bioaccumulative potential
Log P (n-octanol/water): 0.8
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:
No SARA Hazards.

Massachusetts Right To Know Components:
No components are subject to the Massachusetts Right to Know Act.
Pennsylvania Right To Know Components:
No components are subject to the Pennsylvania Right to Know Act.
New Jersey Right To Know Components:
No components are subject to the New Jersey Right to Know Act.

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:
- The Australian Inventory of Industrial Chemicals: Chemical: Acetamide, N-[2-(5-methoxy-1H-indol-3-yl)ethyl]-
- FDA Requirements: Implantation or injectable dosage form new animal drugs. Melatonin implant. ... Indications for use: For use in healthy male and female kit and adult female mink (Mustela vison) to accelerate the fur priming cycle. Limitations: For subcutaneous implantation in mink only. Do not implant potential bre

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.