Formaldehyde

Classification

Flammable gas Cat 1; Acute toxicity (oral) Cat 4; Acute toxicity (inhalation) Cat 2; Skin corrosion Cat 1B; Skin sensitization Cat 1; Germ cell mutagenicity Cat 2; Carcinogenicity Cat 1B

This classification is for formaldehyde gas. Formalin and other formaldehyde solutions are classified differently depending on concentration, so always check the SDS for the product you use.

Hazard statements

• H220 Extremely flammable gas.
• H302 Harmful if swallowed.
• H314 Causes severe skin burns and eye damage.
• H317 May cause an allergic skin reaction.
• H330 Fatal if inhaled.
• H341 Suspected of causing genetic defects.
• H350 May cause cancer.

Key precautionary statements

• P203 Obtain, read and follow all safety instructions before use.
• P260 Do not breathe dust/fume/gas/mist/vapors/spray.
• P280 Wear protective gloves/protective clothing/eye protection/face protection.
• P284 In case of inadequate ventilation, wear respiratory protection.
• P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Immediately rinse with water for several minutes.
• P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
• P305+P354+P338 IF IN EYES: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
• P316 Get emergency medical help immediately.

OSHA regulates formaldehyde under its own standard, 29 CFR 1910.1048: 0.75 ppm as an 8-hour TWA, 2 ppm as a 15-minute STEL, and an action level of 0.5 ppm (8-hour TWA) that triggers periodic exposure monitoring and medical surveillance. NIOSH treats formaldehyde as a potential occupational carcinogen; its REL is 0.016 ppm TWA with a 0.1 ppm ceiling for any 15-minute period. ACGIH also flags formaldehyde as a dermal and respiratory sensitizer. Cal/OSHA uses the same 0.75 ppm TWA and 2 ppm STEL. State OSHA plans may set different limits.

• Appearance: Nearly colorless gas; usually handled as an aqueous solution (formalin)
• Odor: Pungent, suffocating
• Molecular weight: 30.0
• Boiling point: -6°F (-21°C)
• Freezing point: -134°F (-92°C)
• Flash point: Not applicable (flammable gas). A 36.5–38% formalin solution has a flash point of 147°F (64°C), closed cup (supplier SDS)
• Autoignition temperature: 795°F (424°C)
• Explosive limits: LEL 7.0%, UEL 73%
• Vapor pressure: Greater than 1 atm
• Relative gas density: 1.04 (slightly heavier than air)
• Water solubility: Miscible

Inhalation

Irritates the eyes, nose, throat and respiratory system, causing tearing, cough and wheezing. High concentrations can be fatal if inhaled.

Skin

Solutions cause severe skin burns. Formaldehyde is a skin sensitizer: after sensitization, later contact can trigger an allergic skin reaction.

Eyes

Irritation and tearing from vapor; liquid splashes cause severe eye damage.

Ingestion

Harmful if swallowed. Formaldehyde solutions are corrosive to the mouth, throat and stomach.

Target organs

Eyes, respiratory system

Long-term effects

NIOSH considers formaldehyde a potential occupational carcinogen, with nasal cancer as the cancer site. Under GHS it is classified as a carcinogen (May cause cancer) and is suspected of causing genetic defects. OSHA requires materials that can release formaldehyde above 0.5 ppm to carry a "May cause cancer" hazard statement.

Gloves

Nitrile rubber. For full contact, use gloves at least 0.4 mm thick (breakthrough time 480 minutes); for splash contact, at least 0.2 mm (breakthrough time 60 minutes), per the Sigma-Aldrich SDS for 36.5–38% formaldehyde solution.

Eyes and face

Tightly fitting chemical goggles, plus a face shield where splashing is possible. OSHA requires goggles or face shields to prevent contact with liquids containing 1% or more formaldehyde, and an eyewash in the immediate work area where solutions of 0.1% or more can splash into eyes.

Respiratory

OSHA requires respirators where engineering controls cannot keep exposure below the PELs and in emergencies, under a 29 CFR 1910.134 program. Above the NIOSH REL, NIOSH recommends only a full-facepiece pressure-demand SCBA or a supplied-air respirator with auxiliary SCBA; use a full-facepiece gas mask with a formaldehyde canister for escape only.

Clothing

Impervious chemical protective clothing to prevent skin contact with liquids containing 1% or more formaldehyde, with quick drench showers where such solutions can splash the skin. Full body protection is required to enter areas above 100 ppm.

Store in a cool, dry, well-ventilated place in tightly closed containers kept upright. Keep away from heat, sparks and open flames. Where airborne levels exceed the OSHA TWA or STEL, the area must be a posted, restricted regulated area.

Use with local exhaust ventilation or in a fume hood. Avoid contact with skin and eyes and avoid breathing vapor or mist. Take measures against static discharge. Pure formaldehyde tends to polymerize.

Keep away from

• Strong oxidizers
• Alkalis
• Acids, including hydrochloric acid (the mixture can form bis(chloromethyl) ether, a potent carcinogen)
• Phenols
• Urea

• Evacuate nonessential people and ventilate the area. Responders need respiratory protection; enter unknown concentrations only with SCBA and full body protection.
• Remove all ignition sources. Vapors can build up in low areas.
• Contain the spill and keep it out of drains and waterways.
• Soak up with inert absorbent and place in suitable closed containers for disposal as hazardous waste.
• For transport incidents involving formaldehyde solution (UN2209), refer to ERG Guide 153.

Suitable extinguishing media

• Water spray (also to cool unopened containers)
• Alcohol-resistant foam
• Dry chemical
• Carbon dioxide (CO2)

Special hazards

Formaldehyde gas is flammable between 7% and 73% in air. Formalin solutions are combustible, and vapors can collect in low areas. Fires produce carbon oxides. Firefighters should wear SCBA.

• OSHA Hazard Communication (29 CFR 1910.1200): Hazardous chemical; SDS, labels and training required. Applies to formaldehyde gas, solutions over 0.1% and materials that release 0.1 ppm or more.
• OSHA Formaldehyde standard (29 CFR 1910.1048): PEL 0.75 ppm TWA, STEL 2 ppm, action level 0.5 ppm. Requires exposure monitoring, regulated areas, medical surveillance, eyewash and drench showers, and annual training for workers exposed at 0.1 ppm or more.
• EPA CERCLA (40 CFR 302.4): Hazardous substance, reportable quantity 100 lb.
• EPA EPCRA Section 302 (40 CFR 355): Extremely hazardous substance, threshold planning quantity 500 lb; release reportable quantity 100 lb.
• EPA EPCRA Section 313 (TRI) (40 CFR 372.65): Listed.
• EPA Clean Air Act 112(r) (40 CFR 68.130): Formaldehyde (solution) is a regulated toxic substance, threshold quantity 15,000 lb.
• DOT (49 CFR 172.101): Formaldehyde solutions with 25% or more formaldehyde ship as UN2209, Class 8, PG III.

• NIOSH Pocket Guide to Chemical Hazards: Formaldehyde
• OSHA 29 CFR 1910.1048, Formaldehyde
• OSHA Occupational Chemical Database: Formaldehyde
• PubChem: Formaldehyde (CID 712)
• Sigma-Aldrich SDS: Formaldehyde solution, 36.5–38%