1-Methylnaphthalene

1Identification

Name

1-Methylnaphthalene

IUPAC name

1-methylnaphthalene

CAS number

90-12-0

EC number

201-966-8

Molecular formula

C11H10

Molecular weight

142.2 g/mol

InChIKey

QPUYECUOLPXSFR-UHFFFAOYSA-N

SMILES

CC1=CC=CC2=CC=CC=C12

PubChem CID

7002

Synonyms

alpha-Methylnaphthalene, Naphthalene, 1-methyl-, 1-methyl-naphthalene, 1-Methyl naphthalene, RefChem:76402, Naphthalene, methyl-, 1-Methylnapththalene, alpha-methyl naphthalenes, Methylnaphthalene(mix), .alpha.-Methylnaphthalene, Methyl-1-naphthalene, Methyl naphthalene, Naphthalene, alpha-methyl-, 1-Methylnaphthalene, analytical standard

Recommended uses

• Produced from coal tar and used to make dyes and resins; Used as a solvent for pesticides; Present in asphalt and smoke from burning cigarettes and wood; [ACGIH]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Used as a solvent and to make surfactants, insecticides, and other chemicals; [HSDB] Used to make dyes, resins, and other organic chemicals; [ACGIH]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• For methylnaphthalene (USEPA/OPP Pesticide Code: 054002) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./
  Hazardous Substances Data Bank (HSDB)
• Fuel Intermediate Not Known or Reasonably Ascertainable
  EPA Chemical Data Reporting (CDR)
• Intermediate
  EPA Chemical Data Reporting (CDR)

Use categories: Fragrance Ingredients · Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes · Flavoring Agents -> JECFA Flavorings Index · Environmental transformation -> Pesticide transformation products (metabolite, successor)

Description

• Methylnaphthalene appears as bluish-brown oil or a clear yellow liquid. Coal tar or mothball odor. (NTP, 1992)
  CAMEO Chemicals
• 1-methylnaphthalene is a colorless liquid. Freezing point -22 °C (7.6 °F). Boiling point 240-243 °C (464-469 °F). Flash point 82 °C (180 °F). Denser than water. Derived from coal tar and used in organic synthesis.
  CAMEO Chemicals
• 1-methylnaphthalene is a methylnaphthalene carrying a methyl substituent at position 1. It has a role as a carcinogenic agent and a plant metabolite.
  ChEBI

2Hazard identification

Signal word

Danger

Pictograms

GHS07, GHS08, GHS09

Classification source

European Chemicals Agency (ECHA)

Precautionary statements

Other reported classifications

6 classification records exist across sources. Differences usually reflect purity, physical form or impurities.

NFPA 704 rating

• 1 - Materials that, under emergency conditions, can cause significant irritation.
  Hazardous Substances Data Bank (HSDB)
• 1 - Materials that must be preheated before ignition can occur. Materials require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur.
  Hazardous Substances Data Bank (HSDB)
• 0 - Materials that in themselves are normally stable, even under fire conditions.
  Hazardous Substances Data Bank (HSDB)

Health hazards

• SYMPTOMS: Exposure to this compound may cause skin irritation. It may also cause photosensitization. The vapors, fumes or direct contact with the solid may be irritating to the eyes. Inhalation of the vapors may produce airway irritation, headache, nausea, weakness and collapse. Long term overexposure has led to corneal changes. Ingestion may lead to systemic poisoning involving the gastrointestinal tract, kidneys and blood-forming tissue. Individuals with erythrocytic glucose-6-phosphate dehydrogenase deficiency may be particularly susceptible to possible hemolytic effects.
  CAMEO Chemicals
• Harmful if inhaled. Liquid causes irritation of the eyes and skin and skin photosensitization. Harmful if swallowed. Chronic exposure may cause liver or kidney damage. (USCG, 1999)
  CAMEO Chemicals

Fire hazards

• This chemical is probably combustible. (NTP, 1992)
  CAMEO Chemicals
• This chemical is combustible. (NTP, 1992)
  CAMEO Chemicals
• Combustible. Above 82 °C explosive vapour/air mixtures may be formed.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Hazards summary

• There are no studies of humans exposed to 1-methylnaphthalene or 2-methylnaphthalene. [ATSDR ToxFAQs] Minimal Risk Level (oral chronic) = 0.7 mg/kg/day (Resp.); [ATSDR] 1-Methylnaphthalene (1-MN) and 2-Methylnaphthalene (2-MN) are respiratory tract irritants. [ACGIH] See Naphthalene.
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• A skin irritant and photosensitizer; [HSDB] May cause skin, eye, and respiratory tract irritation; Can cause photosensitization; [CAMEO] An irritant; Can be absorbed through skin; [MSDSonline] Photosensitization not mention in 2007 ACGIH documentation of TLV, nor in ATSDR toxic profile; PubMed search by CAS numbers found no records relating to photosensitization; See 1-Methylnaphthalene and 2-Methylnaphthalene.
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

3Composition / information on ingredients

This page describes the pure substance. Commercial products may be solutions or mixtures. Check Section 3 of your supplier's SDS for concentrations and other ingredients.

4First-aid measures

• EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water.
  CAMEO Chemicals

Symptoms of exposure

• Redness.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness. Pain.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Acute exposure to PAHs causes irritation and inflammation of the skin and lung tissue. (A10)
  Toxin and Toxin Target Database (T3DB)

5Fire-fighting measures

• If material on fire or involved in fire: Use water in flooding quantities as fog. Solid streams of water may be ineffective. Solid streams of water may spread fire. Use foam, dry chemical, or carbon dioxide. /Methylnaphthalenes, liquid/
  Hazardous Substances Data Bank (HSDB)
• Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Methylnaphthalenes, liquid/
  Hazardous Substances Data Bank (HSDB)
• Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. A water spray may also be used.
  Hazardous Substances Data Bank (HSDB)

6Accidental release measures

Isolation and evacuation

• Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary. FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)
  CAMEO Chemicals

Spill cleanup

• Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. Do NOT let this chemical enter the environment.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. Then, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.
  Hazardous Substances Data Bank (HSDB)
• Environmental considerations: Water spill: Use natural barriers or oil spill booms to limit spill travel. Remove trapped material with suction hoses. /Methylnaphthalenes, liquid/
  Hazardous Substances Data Bank (HSDB)
• Environmental considerations: Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents. /Methylnaphthalenes, liquid/
  Hazardous Substances Data Bank (HSDB)

7Handling and storage

• Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• You should store this material under ambient temperatures.
  Hazardous Substances Data Bank (HSDB)
• Conditions for safe storage, including any incompatibilities: Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage.
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

Personal protective equipment

• RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)
  CAMEO Chemicals
• Rubber gloves, safety goggles, coveralls, rubber shoes or boots, and hydrocarbon vapor canister mask. (USCG, 1999)
  CAMEO Chemicals
• ... Wear appropriate chemical protective gloves, boots and goggles ... /Methylnaphthalenes, liquid/
  Hazardous Substances Data Bank (HSDB)
• Eye/face protection: Face shield and safety glasses Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
  Hazardous Substances Data Bank (HSDB)

9Physical and chemical properties

10Stability and reactivity

Reactivity

• METHYLNAPHTHALENE is incompatible with strong oxidizing agents. It is also incompatible with peroxides and oxygen. (NTP, 1992)
  CAMEO Chemicals
• 1-METHYLNAPHTHALENE is sensitive to heat. Reacts with strong oxidizing agents. Incompatible with oxygen and peroxides (NTP, 1992).
  CAMEO Chemicals
• Insoluble in water.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• This compound is incompatible with strong oxidizers.
  Hazardous Substances Data Bank (HSDB)
• It is combustible, reacts with strong oxidizing agents, and is sensitive to heat.
  Hazardous Substances Data Bank (HSDB)
• Combustible when exposed to ... oxidizers.
  Hazardous Substances Data Bank (HSDB)

Chemical stability

• This chemical is stable under normal laboratory conditions. Solutions of this chemical in water, DMSO, 95% ethanol or acetone should be stable for 24 hours under normal lab conditions.
  Hazardous Substances Data Bank (HSDB)

11Toxicological information

Short-term exposure effects

• The substance is irritating to the eyes.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Long-term exposure effects

• Repeated or prolonged inhalation may cause effects on the lungs.
  ILO-WHO International Chemical Safety Cards (ICSCs)

12Ecological information

Not available in the public sources we compile. Check Section 12 of the supplier's SDS.

13Disposal considerations

• SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.
  Hazardous Substances Data Bank (HSDB)
• The following wastewater treatment technology has been investigated for naphthalene: Biological treatment. /Naphthalene/
  Hazardous Substances Data Bank (HSDB)
• Waste treatment methods. Product: This combustible material may be burned in a chemical incinerator equipped with an afterburner and scrubber. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Contaminated packaging: Dispose of as unused product.
  Hazardous Substances Data Bank (HSDB)

14Transport information

DOT label

• Class 9
  CAMEO Chemicals

Not available in the public sources we compile. Check Section 14 of the supplier's SDS.

How DOT hazard classes work →

15Regulatory information

• This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Alkyl naphthalenes is produced, as an intermediate or a final product, by process units covered under this subpart. /Alkyl Naphthalenes/
  Hazardous Substances Data Bank (HSDB)
• As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996.
  Hazardous Substances Data Bank (HSDB)

Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →

16Other information

Compiled from PubChem CID 7002 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.