UN Number: 1779 - CAS Number: 64-18-6

Also known as: ACIDE FORMIQUE, Methanoic Acid, Formilic Acid, Aminic Acid, Formic Acid
Information on chemical

Information on chemical

External resources

CAMEO Chemical Database
WISER Substance List


UN number 1779
CAS number 64-18-6
Formula CH2O2

Physical chemical data

Physical State (20°C) Liquid
Physical State (25°C) Liquid
Density (kg/m3)
1220 [Kg/m³] at a temperature of 20°C
Kinematic viscosity (cSt)
1.3172 [cSt] at a temperature of 25°C
Molar mass (g/mol) 46.03
Density of gas (kg/m3) 2.051
Solubility (g/L)
1000000 [g/L] at a temperature of 25°C and salinity of 0‰
Boiling Point (°C) 101
Melting Point (°C) 8.3
Critical temperature (°C) 588
Surface tension (mN/m)
34.38 [mN/m] at a temperature of 25°C
Interfacial tension (mN/m)
1.32 [mN/m] at a temperature of 25°C and salinity of 0‰
Vapour Pressure (Pa)
4399 [Pa] at a temperature of 20°C
Ignition Temperature (°C) 600
Flash Point (°C) 69
Flash Point (Pensky-Martens closed cup) (°C) 69
Flash Point (Cleveland open cup) (°C) 50
Lower explosivity limit (LEL) (volume %) 18
Upper explosivity limit (UEL) (volume %) 57
Vapor enthalpy (J/Kg)
492982 [J/Kg] at a temperature of 101°C
436710 [J/Kg] at a temperature of 25°C
Combus enthalpy (J/Kg) 5531656
Specific heat capacity (J/(Kg·K)) 2151
Henry's constant (mol/(m³·Pa)) 0.017

Behaviour at sea

Log kow -0.22
Log koc 0
Aqueous photolysis (Half-life) Not photolysable
Biodegradation in estuary environment (Half-life) (days) Not hydrolysable
Bioconcentration factor (BCF) 3.2

Additional data

Colour colourless
Odour penetrating odour
MARPOL pollution category
Category Description
Y Noxious Liquid Substances which, if discharged into the sea from tank cleaning or deballasting operations, are deemed to present a hazard to either marine resources or human health or cause harm to amenities or other legitimate uses of the sea and therefore justify a limitation on the quality and quantity of the discharge into the marine environment.

Transportation data

Transport mode Bulk,Packaged
Package group II
State liquid
Temperature (°C) ambient
Pressure (Pa) under pressure
Family name organic acids

Reactivity data

Abilities Miscible in water.
Acid(s) Yes
Base(s) Yes
Oxidizing agents Yes
Organic substance Yes

GESAMP Hazard profile

Bioaccumulation in logPow (A1A) 0 - e <1, or > ca.7, or Mol. Wt. > 1000
Bioaccumulation (A1) 0 - No potential to bioaccumulate
Biodegradation (A2) R - Readily biodegradable
Acute aquatic toxicity (B1) (LC/EC/IC50 (mg/l)) 2 - Slightly toxic
Acute mammalian toxicity by swallowing (C1) (LD50 (mg/kg)) 1 - Slight
Acute mammalian toxicity by skin penetration (C2) (LD50 (mg/kg)) 1 - Slight
Acute mammalian toxicity by inhalation (C3) (LC50 (mg/l)) 2 - Moderate
Skin irritation/corrosivity (D1) 3C - Corrosive
Eye irritation/corrosivity (D2) 3 - Severely irritating, with irreversible corneal injury
Interference with coastal amenities (E2) D - Dissolver
Effects on wildlife and bottom habitats (E3) 3 - Is highly acutely toxic; and/or is severely irritant or corrosive to skin or eyes; and/or is carcinogenic, mutagenic or reprotoxic; and/or is a floater or persistent floater with associated health effects

Human toxicity threshold

Corrosive Flammable Toxic
Hazard statements
H226 Flammable liquid and vapour.
H302 Harmful if swallowed.
H314 Causes severe skin burns and eye damage.
H331 Toxic if inhaled.
Precautionary statements
P210 Keep away from heat/sparks/open flames/hot surfaces. No smoking.
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P303 + P361 + P353 IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower.
P305 + P351 + P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
TEEL-1 (mg/m3) 0.92 ppm
TEEL-2 (mg/m3) 0.92 ppm
TEEL-3 (mg/m3) 30 ppm


Lowest median lethal concentration (LC50) on crustacean (mg/l) 34
Lowest median lethal concentration (LC50) on fishes (mg/l) 46
Assessment factor (AF)
500 on the Short term
Predicted No Effect Concentration (PNEC) (µg/l)
200 [µg/l] on the Short term
Incident reports

Incident reports

No incident reports available

Emergency Response Guidebook

Emergency Response Guidebook

Guide number: 153

See the guide or download the emergency response guidebook

At sea emergency guide

At sea emergency guide

Emergency schedule: 8-05


Emergency procedures

Spillage on deck

Wash overboard with copious quantities of water.

Spillage under deck

Collect spillage, where practicable, using absorbent material for liquids, for safe disposal.

Fire on deck

Use water spray.

Fire under deck

Batten down; use ship's fixed fire-fighting installation. Otherwise adopt action as for "On deck".

Special equipment to be carried

Protective clothing (gloves, boots, coveralls, headgear).
Self-contained breathing apparatus.
Spray nozzles.

Remarks by UN no.

• FORMIC ACID (UN No. 1779)
Turn ship off-wind.

Decision trees

Decision trees

No decision trees available

No additional data

last modified 2020-12-14T09:02:31+00:00