Naphthalene

1Identification

Name

Naphthalene

IUPAC name

naphthalene

CAS number

91-20-3

EC number

202-049-5

Molecular formula

C10H8

Molecular weight

128.17 g/mol

InChIKey

UFWIBTONFRDIAS-UHFFFAOYSA-N

SMILES

C1=CC=C2C=CC=CC2=C1

PubChem CID

931

Synonyms

naphthalene, Naphthalin, Tar camphor, White tar, Albocarbon, Naphthene, Camphor tar, naphtalene, Naphthaline, Moth balls, Moth flakes, Dezodorator, Naftalen, Mighty 150

Recommended uses

• The primary use for naphthalene is in the production of phthalic anhydride. However, o-xylene is replacing naphthalene as the preferred raw material for phthalic anhydride production.
  EPA Hazardous Air Pollutants
• Naphthalene is produced from petroleum or coal tars. Naphthalene is used mainly as an intermediate in the synthesis of organic chemicals (plastics, insecticides, fungicides, etc.). It has been used as a household moth repellent. [ACGIH] Naphthalene is produced from incomplete combustion, e.g., burning fossil fuels, forest fires, and smoking cigarettes. It is present in jet and diesel fuel. Its use as a moth repellent has decreased since the introduction of p-dichlorobenzene. Naphthalene is one of the major components of creosote, and the highest concentrations in industrial environments occur in workplaces producing creosote-impregnated timbers. [See Reference #1]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Smoking cigarettes [Category: Food & Drugs]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Fuel agents Fuel Abrasives Surfactant (surface active agent) Monomers Processing aids not otherwise specified Binder Solvent Intermediate Soil amendments (fertilizers) Not Known or Reasonably Ascertainable
  EPA Chemical Data Reporting (CDR)
• Fuel agents Fuel Not Known or Reasonably Ascertainable Intermediate
  EPA Chemical Data Reporting (CDR)

Description

• Naphthalene can cause cancer according to The National Toxicology Program.
  California Office of Environmental Health Hazard Assessment (OEHHA)
• Naphthalene appears as a white crystalline volatile solid with a strong coal-tar odor. The solid is denser than water and insoluble in water. Burns, but may be difficult to ignite. In the molten form it is very hot. Exposure to skin must be avoided. Also the vapors given off by the material may be toxic. Used as a moth repellent, fumigant, lubricants, and to make other chemicals, and for many other uses
  CAMEO Chemicals
• Naphthalene, methylnaphthalenes appears as a black liquid with the odor of coal tar. Negligibly soluble in water. Slightly denser than water. Vapors, fumes or direct contact may irritate the eyes. Direct skin contact may produce severe burns. Inhalation may produce mucous irritation, dizziness, loss of coordination, cardiovascular collapse and death.
  CAMEO Chemicals

2Hazard identification

Signal word

Warning

Pictograms

GHS07, GHS08, GHS09

Classification source

Regulation (EC) No 1272/2008 of the European Parliament and of the Council

Precautionary statements

Other reported classifications

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

NFPA 704 rating

• 2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury.
  Hazardous Substances Data Bank (HSDB)
• 2 - Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. Materials would not under normal conditions form hazardous atmospheres with air, but under high ambient temperatures or under moderate heating could release vapor in sufficient quantities to produce hazardous atmospheres with air.
  Hazardous Substances Data Bank (HSDB)
• 0 - Materials that in themselves are normally stable, even under fire conditions.
  Hazardous Substances Data Bank (HSDB)

Health hazards

• Excerpt from ERG Guide 133 [Flammable Solids]: Fire may produce irritating and/or toxic gases. Contact may cause burns to skin and eyes. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control or dilution water may cause environmental contamination. (ERG, 2024)
  CAMEO Chemicals
• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: TOXIC and/or CORROSIVE; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause environmental contamination. (ERG, 2024)
  CAMEO Chemicals
• · Fire may produce irritating and/or toxic gases. · Contact may cause burns to skin and eyes. · Contact with molten substance may cause severe burns to skin and eyes. · Runoff from fire control or dilution water may cause environmental contamination.
  Emergency Response Guidebook (ERG)

Fire hazards

• Excerpt from ERG Guide 133 [Flammable Solids]: Flammable/combustible material. May be ignited by friction, heat, sparks or flames. Some may burn rapidly with flare-burning effect. Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence. Substance may be transported in a molten form at a temperature that may be above its flash point. May re-ignite after fire is extinguished. (ERG, 2024)
  CAMEO Chemicals
• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Corrosives in contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. For electric vehicles or equipment, ERG Guide 147 (lithium ion or sodium ion batteries) or ERG Guide 138 (sodium batteries) should also be consulted. (ERG, 2024)
  CAMEO Chemicals
• · Flammable/combustible material. · May be ignited by friction, heat, sparks or flames. · Some may burn rapidly with flare-burning effect. · Powders, dusts, shavings, borings, turnings or cuttings may explode or burn with explosive violence. · Substance may be transported in a molten form at a temperature that may be above its flash point. · May re-ignite after fire is extinguished.
  Emergency Response Guidebook (ERG)

Hazards summary

• Naphthalene is used in the production of phthalic anhydride; it is also used in mothballs. Acute (short- term) exposure of humans to naphthalene by inhalation, ingestion, and dermal contact is associated with hemolytic anemia, damage to the liver, and neurological damage. Cataracts have also been reported in workers acutely exposed to naphthalene by inhalation and ingestion. Chronic (long-term) exposure of workers and rodents to naphthalene has been reported to cause cataracts and damage to the retina. Hemolytic anemia has been reported in infants born to mothers who "sniffed" and ingested naphthalene (as mothballs) during pregnancy.
  EPA Hazardous Air Pollutants
• Ingestion of high doses of naphthalene can induce methemoglobinemia and precipitate subacute hemolysis. The lethal dose orally for an adult is 5-15 grams. Workers deficient in glucose-6-phosphate dehydrogenase are more susceptible to hemolysis. A 1956 study found cataracts in 8 of 21 workers who melted naphthalene in open vats. After new procedures to reduce exposures, no further cataracts were reported. [ACGIH] Chronic sniffing of naphthalene containing mothballs can cause liver necrosis. [HSDB] Naphthalene is not hepatotoxic in experimental animal studies or in human exposures. [Zimmerman, p. 367] Suspected germ cell mutagen (3B); [MAK]
  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
• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Refer to the "General First Aid" section. Specific First Aid: For corrosives, in case of contact, immediately flush skin or eyes with running water for at least 30 minutes. Additional flushing may be required. (ERG, 2024)
  CAMEO Chemicals
• General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).
  Emergency Response Guidebook (ERG)
• (General first aid procedures) Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Skin: Molten flush immediately/solid-liquid soap wash promptly Breathing: Respiratory support Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.
  The National Institute for Occupational Safety and Health (NIOSH)

Symptoms of exposure

• Headache. Weakness. Sweating. Nausea. Vomiting. Further see Ingestion.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• See Inhalation.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness.
  ILO-WHO International Chemical Safety Cards (ICSCs)

5Fire-fighting measures

• If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Solid streams of water may be ineffective. Use "alcohol" foam, dry chemical or carbon dioxide. /Naphthalene, crude or refined/
  Hazardous Substances Data Bank (HSDB)
• If material on fire or involved in fire: Solid streams of water may spread fire. Use water in flooding quantities as fog. Use dry chemical, graphite or dry earth. /Naphthalene, molten/
  Hazardous Substances Data Bank (HSDB)
• If material is on fire or involved in fire: Use water in flooding quantities as fog. Use foam, dry chemical, or carbon dioxide. Cool all affected containers with flooding quantities of water. Keep run-off water out of sewers and water sources.
  Hazardous Substances Data Bank (HSDB)

Hazardous combustion products

• Hazardous decomposition products formed under fire conditions. - Carbon oxides.
  Hazardous Substances Data Bank (HSDB)

6Accidental release measures

Isolation and evacuation

• Excerpt from ERG Guide 133 [Flammable Solids]: IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 25 meters (75 feet) in all directions. LARGE SPILL: Consider initial downwind evacuation for at least 100 meters (330 feet). 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
• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: 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

• Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Do NOT wash away into sewer. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Environmental considerations: Water spill: Use natural barriers or oil spill booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates. /Naphthalene, molten/
  Hazardous Substances Data Bank (HSDB)
• Environmental considerations: Water spill: Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. If dissolved, in region of 10 ppm or greater concentration, apply activated carbon at ten times the spilled amount. Remove trapped material with suction hoses. Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates. /Naphthalene, crude or refined/
  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./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. /Naphthalene, crude or refined/
  Hazardous Substances Data Bank (HSDB)

7Handling and storage

• Separated from strong oxidants and food and feedstuffs. Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Without inert-gas blanketing and at the temperature normally used for the storage of molten naphthalene, i.e., 90 °C, the vapors above the liquid are within the flammability limits. Thus, storage tanks containing molten naphthalene have a combustible mixture in the vapor space and care must be taken to eliminate all sources of ignition around such systems. Naphthalene dust can form explosive mixtures with air which necessitates the design and operation of solid handling systems.
  Hazardous Substances Data Bank (HSDB)
• Store in a cool, dry, well-ventilated location. Separate from oxidizing materials. May be stored under nitrogen gas.
  Hazardous Substances Data Bank (HSDB)
• Always store in a cool, dry, dark place.
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

Personal protective equipment

• Excerpt from NIOSH Pocket Guide for Naphthalene: Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact. Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact. Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated. Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced. Change: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises. (NIOSH, 2024)
  CAMEO Chemicals
• Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE. Structural firefighters' protective clothing provides thermal protection but only limited chemical protection. (ERG, 2024)
  CAMEO Chemicals
• Hand protection: Handle with gloves.
  Hazardous Substances Data Bank (HSDB)
• Eye protection: Safety glasses with side-shields conforming to EN166 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)

Respirator recommendations

• NIOSH/OSHA Up to 100 ppm: (APF = 10) Any air-purifying half-mask respirator with organic vapor cartridge(s) in combination with an N95, R95, or P95 filter. The following filters may also be used: N99, R99, P99, N100, R100, P100. Click here for information on selection of N, R, or P filters.* (APF = 10) Any supplied-air respirator* Up to 250 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode* (APF = 50) Any air-purifying full-facepiece respirator equipped with organic vapor cartridge(s) in combination with an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters.
  The National Institute for Occupational Safety and Health (NIOSH)

9Physical and chemical properties

10Stability and reactivity

Reactivity

• Vigorous reactions, sometimes amounting to explosions, can result from the contact between aromatic hydrocarbons, such as NAPHTHALENE, and strong oxidizing agents. They can react exothermically with bases and with diazo compounds. Substitution at the benzene nucleus occurs by halogenation (acid catalyst), nitration, sulfonation, and the Friedel-Crafts reaction. Naphthalene, camphor, glycerol, or turpentine will react violently with chromic anhydride [Haz. Chem. Data 1967. p 68]. Friedel-Crafts acylation of naphthalene using benzoyl chloride, catalyzed by AlCl3, must be conducted above the melting point of the mixture, or the reaction may be violent [Clar, E.
  CAMEO Chemicals
• A mixture containing NAPHTHALENE and METHYLNAPHTHALENES may react vigorously with strong oxidizing agents. Can react exothermically with bases and with diazo compounds. Naphthalene reacts violently with chromic anhydride [Haz. Chem. Data 1967. p 68]. Friedel-Crafts acylation of naphthalene using benzoyl chloride, catalyzed by AlCl3, must be conducted above the melting point of the mixture, or the reaction may be violent [Clar, E. et al., Tetrahedron, 1974, 30, 3296].
  CAMEO Chemicals
• Highly flammable. Insoluble in water.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• Naphthalene ...will react violently with chromic anhydride.
  Hazardous Substances Data Bank (HSDB)
• Strong oxidizers, chromic anhydride.
  Hazardous Substances Data Bank (HSDB)
• Reacts violently with chromium trioxide, aluminum chloride and benzoyl chloride.
  Hazardous Substances Data Bank (HSDB)

Chemical stability

• Stable under recommended storage conditions.
  Hazardous Substances Data Bank (HSDB)

11Toxicological information

Target organs

• Nervous Respiratory
  EPA Integrated Risk Information System (IRIS)
• Eyes, skin, blood, liver, kidneys, central nervous system
  The National Institute for Occupational Safety and Health (NIOSH)

Short-term exposure effects

• The substance may cause effects on the blood. This may result in lesions of blood cells (haemolysis). The effects may be delayed. Ingestion could cause death. Medical observation is indicated.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Long-term exposure effects

• The substance may have effects on the blood. This may result in chronic haemolytic anaemia. The substance may have effects on the eyes. This may result in development of cataract. This substance is possibly carcinogenic to humans.
  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

• Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U165, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
  Hazardous Substances Data Bank (HSDB)
• SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal.
  Hazardous Substances Data Bank (HSDB)
• The following wastewater treatment technologies have been investigated for naphthalene: biological treatment.
  Hazardous Substances Data Bank (HSDB)

14Transport information

UN numbers: UN 1334, UN 2304

Shipping name

• UN 1334; Naphthalene, crude or Naphthalene, refined
  Hazardous Substances Data Bank (HSDB)
• UN 2304; Naphthalene, molten
  Hazardous Substances Data Bank (HSDB)

DOT hazard class

• Naphthalene, crude or Naphthalene, refined
  US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
• Marine pollutant
  US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172
• Napthalene, molten
  US Code of Federal Regulations, Hazardous Materials, 49 CFR Part 172

DOT label

• Flammable Solid
  CAMEO Chemicals
• Corrosive
  CAMEO Chemicals

UN classification

• UN Hazard Class: 4.1; UN Pack Group: III
  ILO-WHO International Chemical Safety Cards (ICSCs)

Emergency Response Guidebook

• 2304 133
  Emergency Response Guidebook (ERG)
• 1334 133(crude or refined)
  The National Institute for Occupational Safety and Health (NIOSH)

How DOT hazard classes work →

15Regulatory information

• Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Naphthalene is included on this list.
  Hazardous Substances Data Bank (HSDB)
• The Agency has completed its assessment of the human health and ecological risks associated with the use of pesticide products containing naphthalene. The Agency has determined that naphthalene-containing products are eligible for reregistration provided that label amendments are made as outlined in Chapter V. ... Based on its evaluation of naphthalene, the Agency has determined that products containing naphthalene, unless labeled and used as specified in this document, would present risks inconsistent with FIFRA.
  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 safety standards, such as those described in the Food Quality Protection Act of 1996. Naphthalene is found on List A, which contains most pesticides that are used on foods and, hence, have a high potential for human exposure.
  Hazardous Substances Data Bank (HSDB)
• Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations.
  Hazardous Substances Data Bank (HSDB)
• Naphthalene is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.
  Hazardous Substances Data Bank (HSDB)
• Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.4 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV.D.3.b).
  Hazardous Substances Data Bank (HSDB)
• Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date: 8/4/95; Reporting date: 10/3/95.
  Hazardous Substances Data Bank (HSDB)
• U165; As stipulated in 40 CFR 261.33, when naphthalene, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).
  Hazardous Substances Data Bank (HSDB)

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

16Other information

Compiled from PubChem CID 931 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.