Hazard Info

Physical Hazards

Physical Hazard: Explosives
Definition: Includes Explosive substances and mixtures, explosive articles, and substances as well as mixtures and articles that are manufactured to produce a practical explosive or pyrotechnic effect.

  • Hazard Category: Unstable Explosive
  • Signal Word: Danger
  • Hazard Statement: Unstable Explosive
  • Symbols: hazard: (click image to enlarge), transport: n/a
  • Hazard Category: Division 1.1
  • Signal Word: Danger
  • Hazard Statement: Explosion; mass explosion hazard
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Division 1.2
  • Signal Word: Danger
  • Hazard Statement: Explosion; severe projection hazard
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Division 1.3
  • Signal Word: Danger
  • Hazard Statement: Explosion; fire, blast or projection hazard
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Division 1.4
  • Signal Word: Warning
  • Hazard Statement: Fire or projection hazard
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Division 1.5
  • Signal Word: Danger
  • Hazard Statement: May mass explode in fire
  • Symbols: hazard: n/a, transport: (click image to enlarge)
  • Hazard Category: Division 1.6
  • Signal Word: n/a
  • Hazard Statement: n/a
  • Symbols: hazard: n/a, transport: (click image to enlarge)
Additional Information: Explosive substances and mixtures – Solid or liquid substance or mixture which, by chemical reactive, is in itself capable of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings.
Pyrotechnic substance/mixture – Substance/mixture designed to produce an effect by heat, light, sound, gas, or smoke or a combination of these as the result of non-detonative self-sustaining exothermic chemical reactions.
Explosive articles – Article containing one or more explosive substance or mixtures.
Pyrotechnic article – Article containing one or more pyrotechnic substances or mixtures.


Physical Hazard: Flammable Gases
Definition: A gas having a flammable range with air at 20 C and standard pressure of 101.3 kPa.

  • Hazard Category: Category 1
  • Signal Word: Danger
  • Hazard Statement: Extremely flammable gas.
  • Definition: Gases ignitable when in mixture of = 13% in air or flammable range with air of >/=12% (regardless of the lower flammable limit).
  • Symbols: hazard: , transport*: (click image to enlarge)
  • Hazard Category: Category 2
  • Signal Word: Warning
  • Hazard Statement: Flammable gas.
  • Definition: Gases, other than those of Category 1, having a flammable range while mixed in air.
  • Symbols: hazard: n/a, transport*: (click image to enlarge)
  • *Note: Under the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, the symbol, number and border line may be shown in black instead of white. The background color stays red in both cases.


Physical Hazard: Flammable Aerosols
Definition: Aerosols, this means aerosol dispensers, are any non-refillable receptacles made of metal, glass or plastics and containing a gas compressed, liquefied or dissolved under pressure, with or without a liquid, paste of powder, and fitted with a release device allowing the contents to be ejected as solid or liquid particles in suspension in a gas, as a foam, paste or powder or in a liquid state or in a gaseous state.

  • Hazard Category: Category 1
  • Signal Word: Danger
  • Hazard Statement: Extremely flammable aerosol.
  • Definition: Extremely flammable aerosols. NOTE: If a product is NOT tested, classify it in Category 1.
  • Symbols: harzard: , transport*: (click image to enlarge)
  • Hazard Category: Category 2
  • Signal Word: Warning
  • Hazard Statement: Flammable aerosol.
  • Definition: Flammable aerosols.
  • Symbols: hazard: , transport*: (click image to enlarge)
  • *Note: Under the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, the symbol, number and border line may be shown in black instead of white. The background color stays red in both cases.
Additional Information: Aerosols are considered for classification as flammable on the basis of: *Their content in flammable components (Liquid, solid, or gases classified as flammable according to the GHS) * Chemical heat of combustion (mainly considered for transport and storage) *Results of the tests: Foam test for foam aerosols (for the worker/consumer), Ignition distance test for spray aerosols (for the worker/consumer), and Enclosed space ignition test for spray aerosols (for transport and storage). Non Flammable Aerosols: if concentration of flammable components = 1% and heat of combustion is < 20 kJ/g. Extremely flammable: if concentration of flammable components >85% and heat of combustion is >/= 30 kJ/g.


Physical Hazard: Oxidizing Gases
Definition: Any gas which may, generally by providing oxygen, cause or contribute to the combustion of other material more than air does.

  • Hazard Category: Category 1
  • Signal Word: Danger
  • Hazard Statement: May cause or intensify fire; oxidizer.
  • Symbols: hazard: , transport: (click image to enlarge)


Physical Hazard: Gases Under Pressure
Definition: Gases contained in a receptacle at a pressure >/= 280 kPa at 20C or as a refrigerated liquid.

  • Hazard Category: Compressed Gas
  • Signal Word: Warning
  • Hazard Statement: Contains gas under pressure; may explode if heated.
  • Definition: Gas entirely gaseous at -50C (includes all gases with a critical temperature = -50C).
  • Symbols: hazard: , transport*: (click image to enlarge)
  • Hazard Category: Liquified Gas
  • Signal Word: Warning
  • Hazard Statement: Contains gas under pressure; may explode if heated.
  • Definition: Partially liquid at temperatures > -50C. *high pressure liquefied gas: critical temperature between -50C and 65C; *low pressure liquefied gas: a gas with a critical temperature > 65C.
  • Symbols: hazard: , transport*: (click image to enlarge)
  • Hazard Category: Dissolved Gas
  • Signal Word: Warning
  • Hazard Statement: Contains gas under pressure; may explode if heated.
  • Definition: Dissolved in a liquid phase solvent.
  • Symbols: hazard: , transport*: (click image to enlarge)
  • Hazard Category: Refrigerated Liquefied Gas
  • Signal Word: Warning
  • Hazard Statement: Contains refrigerated gas; may cause cryogenic burns or injury.
  • Definition: Partially liquid because of its low temperature.
  • Symbols: hazard: , transport*: (click image to enlarge)
  • *Note: Under the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, pictogram elements: (1) Not required for toxic or flammable gases. (2) The symbol, number and border line may be shown in white instead of black. The background stays green in both cases.


Physical Hazard: Flammable Liquids
Definition: Liquids having a flashpoint of not more than 93C. Classified according to flashpoint and initial boiling point.

  • Hazard Category: Category 1
  • Signal Word: Danger
  • Hazard Statement: Extremely flammable liquid and vapor.
  • Definition: Extremely flammable liquid and vapor - Flashpoint < 23C and initial boiling point = 35C.
  • Symbols: hazard: , transport*: (click image to enlarge)
  • Hazard Category: Category 2
  • Signal Word: Danger
  • Hazard Statement: Highly flammable liquid and vapor.
  • Definition: Highly flammable liquid and vapor - Flashpoint < 23C and initial boiling point >35 C.
  • Symbols: hazard: , transport*: (click image to enlarge)
  • Hazard Category: Category 3
  • Signal Word: Warning
  • Hazard Statement: Flammable liquid and vapor.
  • Definition: Flammable liquid and vapor - Flashpoint >/= 23C and = 60C.
  • Symbols: hazard: , transport*: (click image to enlarge)
  • Hazard Category: Category 4
  • Signal Word: Warning
  • Hazard Statement: Combustible liquid.
  • Definition: Combustible liquid - Flashpoint > 60C and = 93C.
  • Symbols: hazard: n/a, transport*: (click image to enlarge)
  • *Note: Under the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, the symbol, number and border line may be shown in black instead of white. The background color stays red in both cases.


Physical Hazard: Flammable Solids

Definition: Solids which are readily combustible, or may cause or contribute to fire through friction. Readily combustible solids are powdered, granular, or pasty substances which are dangerous if they can be easily ignited by brief contact with an ignition source, such as a burning match, and if the flame spreads rapidly.

  • Hazard Category: Category 1
  • Signal Word: Danger
  • Hazard Statement: Flammable solid.
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Category 2
  • Signal Word: Warning
  • Hazard Statement: Flammable solid.
  • Symbols: hazard: , transport: (click image to enlarge)


Physical Hazard: Self-Reactive Substances and Mixtures
Definition: Thermally unstable liquid or solid substances or mixtures liable to undergo a strongly exothermic decomposition even without participation of oxygen (air). This excludes substances and mixtures classified under the GHS as explosives, organic peroxides, or as oxidizing.


  • Hazard Category: Type A
  • Signal Word: Danger
  • Hazard Statement: Heating may cause an explosion.
  • Symbols: hazard: (click image to enlarge), transport: Use appropriate symbol and symbol selection process based on the explosive division (see above)
  • Hazard Category: Type B
  • Signal Word: Danger
  • Hazard Statement: Heating may cause fire or explosion.
  • Symbols: hazard: , transport: (click image to enlarge), and enter explosive pictogram using appropriate symbol and symbol selection process based on the explosive division (see above). Note: For Type B, under the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, special provision 181 may apply (Exemption of explosive label with competent authority approval. See Chapter 3.3 of UN Model Regulations for more details).
  • Hazard Category: Type C
  • Signal Word: Danger
  • Hazard Statement: Heating may cause a fire.
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Type D
  • Signal Word: Danger
  • Hazard Statement: Heating may cause a fire.
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Type E
  • Signal Word: Warning
  • Hazard Statement: Heating may cause a fire.
  • Symbols: hazard: , transport: (click image to enlarge)
  • Hazard Category: Type F
  • Signal Word: Warning
  • Hazard Statement: Heating may cause a fire.
  • Symbols: hazard: , transport: (click image to enlarge)

  • Hazard Category: Type G
  • Signal Word: n/a
  • Hazard Statement: n/a
  • Symbols: hazard: n/a, transport: n/a


  • Physical Hazard: Self-Heating Substances and Mixtures

    • Hazard Category: Category 1
    • Signal Word: Danger
    • Hazard Statement: Self-heating; may catch fire.
    • Symbols: hazard: , transport: (click image to enlarge)
    • Hazard Category: Category 2
    • Signal Word: Warning
    • Hazard Statement: Self-heating in large quantities; may catch fire.
    • Symbols: hazard: , transport: (click image to enlarge)


    Physical Hazard: Pyrophoric Liquids
    Definition: Are liquids/solids which even in small quantities, are liable to ignite within five minutes after coming into contact with air.

    • Hazard Category: Category 1
    • Signal Word: Danger
    • Hazard Statement: Catches fire spontaneously if exposed to air.
    • Symbols: hazard: , transport: (click image to enlarge)


    Physical Hazard: Pyrophoric Solids
    Definition: Are liquids/solids which even in small quantities, are liable to ignite within five minutes after coming into contact with air.

    • Hazard Category: Category 1
    • Signal Word: Danger
    • Hazard Statement: Catches fire spontaneously if exposed to air.
    • Symbols: hazard: , transport: (click image to enlarge)


    Physical Hazard: Substances and Mixtures which, in contact with water, emit Flammable Gases
    Definition: They will be classified if (a) spontaneous ignition takes place in any step of the test procedure; or (b) if there is an evolution of a flammable gas at a rate > 1 liter/kg of substance per hour.

    • Hazard Category: Category 1
    • Signal Word: Danger
    • Hazard Statement: In contact with water releases flammable gases, which may ignite spontaneously.
    • Definition: If in contact with water reacts slowly at ambient temperatures such that the maximum rate of evolution of flammable gas is equal to or greater than 1 liter per kg of substance per hour AND reacts vigorously with water at ambient temperatures and demonstrate generally a tendency for the gas produced to ignite spontaneously, or reacts readily with water at ambient temperatures such that the rate of evolution of flammable gas is equal to or greater than 10 liters per kg of substance over any 1 min.
    • Symbols: hazard: , transport*: (click image to enlarge)
    • Hazard Category: Category 2
    • Signal Word: Danger
    • Hazard Statement: In contact with water releases flammable gas.
    • Definition: If in contact with water it readily reacts with water at ambient temperatures such that the maximum rate of evolution of flammable gas is equal to or greater than 20 liters per kilogram of substance per hour.
    • Symbols: hazard: , transport*: (click image to enlarge)
    • Hazard Category: Category 3
    • Signal Word: Warning
    • Hazard Statement: In contact with water releases flammable gas.
    • Definition: Does not meet any of the above criteria.
    • Symbols: hazard: , transport*: (click image to enlarge)
    • *Note: Under the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, the symbol, number and border line may be shown in black instead of white. The background color stays blue in both cases.
    Additional Information: Classification procedure need not to be applied if the chemical structure does not contain metals or metalloids if: (a) experience in production or handling shows that it does not react with water ( e.g. substance manufactured with water or washed with water); or (b) the substance or mixture is known to be soluble in water to form a stable mixture.


    Physical Hazard: Oxidizing Liquids
    Definition: A liquid which, while in itself is not necessarily combustible, may, generally by yielding oxygen, cause, or contribute to, the combustion of other material. Test results are assessed on the basis of (a) whether the mixture substance/cellulose spontaneously ignites; and (b) the comparison of the mean time taken for the pressure to rise from 690 kPa to 2070 KPa (gauge), with those of the reference substances.

    • Hazard Category: Category 1
    • Signal Word: Danger
    • Hazard Statement: May cause fire or explosion; strong oxidizer.
    • Definition: In the mixture, by mass, of substance (or mixture) and cellulose tested, exhibit a mean pressure rise time less than or equal to the mean pressure rise time of a 1:1 mixture, by mass, of 50% perchloric acid and cellulose.
    • Symbols: hazard: , transport: (click image to enlarge)
    • Hazard Category: Category 2
    • Signal Word: Danger
    • Hazard Statement: May intensify fire; oxidizer.
    • Definition: In the mixture, by mass, of substance (or mixture) and cellulose tested, exhibit a mean pressure rise time less than or equal to the mean pressure rise time of a 1:1 mixture, by mass, of 40% aqueous sodium chlorate and cellulose.
    • Symbols: hazard: , transport: (click image to enlarge)
    • Hazard Category: Category 3
    • Signal Word: Warning
    • Hazard Statement: May intensify fire; oxidizer.
    • Definition: In the mixture, by mass, of substance (or mixture) and cellulose tested, exhibit a mean pressure rise time less than or equal to the mean pressure rise time of a 1:1 mixture, by mass, of 65% aqueous nitric acid and cellulose.
    • Symbols: hazard: , transport: (click image to enlarge)
    Additional Information: Classification procedure for this class need not be applied for organic substances/mixtures if (a) they do not contain oxygen, fluorine or chlorine OR (b) if these elements are chemically bonded only to carbon or hydrogen. For inorganic substances/mixtures, if they do not contain oxygen or halogen atoms.


    Physical Hazard: Oxidizing Solids
    Definition: A solid which, while in itself is not necessarily combustible, may, generally by yielding oxygen, cause, or contribute to, the combustion of other material. Test results are assessed on the basis of (a) Whether the mixture substance/cellulose ignites and burns; and (b) the comparison of the mean burning time with those of the reference mixtures.

    • Hazard Category: Category 1
    • Signal Word: Danger
    • Hazard Statement: May cause fire or explosion; strong oxidizer.
    • Definition: The substance/solid, the 4:1 or 1:1 sample-to-cellulose ratio, by mass tested, exhibits a mean burning time less than or equal to the mean burning time of a 3:2 mixture, by mass, of potassium bromate and cellulose.
    • Symbols: hazard: , transport: (click image to enlarge)
    • Hazard Category: Category 2
    • Signal Word: Danger
    • Hazard Statement: May intensify fire; oxidizer.
    • Definition: The substance/solid, the 4:1 or 1:1 sample-to-cellulose ratio, by mass tested, exhibits a mean burning time less than or equal to the mean burning time of a 2:3 mixture, by mass, of potassium bromate and cellulose.
    • Symbols: hazard: , transport: (click image to enlarge)
    • Hazard Category: Category 3
    • Signal Word: Warning
    • Hazard Statement: May intensify fire; oxidizer.
    • Definition: The substance/solid, in the 4:1 or 1:1 sample-to-cellulose ratio, by mass tested, exhibits a mean burning time less than or equal to the mean burning time of a 3:7 mixture, by mass, of potassium bromate and cellulose.
    • Symbols: hazard: , transport: (click image to enlarge)
    Additional Information: Classification procedure for this class need not be applied for organic substances/mixtures if (a) they do not contain oxygen, fluorine or chlorine OR (b) if these elements are chemically bonded only to carbon or hydrogen. For inorganic substances/mixtures, if they do not contain oxygen or halogen atoms.


    Physical Hazard: Organic Peroxides
    Definition: Liquid or solid organic substances which contain the bivalent -O-O- structure and may be considered derivatives of hydrogen peroxide, where one of both of the hydrogen atoms have been replaces by organic radicals (The term also includes organic peroxide formulations(mixtures). Substances/mixtures are thermally unstable if they (a) undergo exothermic self-accelerating decomposition (b) be liable to explosive decomposition (c) burn rapidly (d) be sensitive to impact of friction (e) react dangerously with other substances OR will be regarded as possessing explosive properties when in laboratory testing the formulation is liable to detonate, to deflagrate rapidly or to show a violent effect when heated under confinement.

    • Hazard Category: Type A
    • Signal Word: Danger
    • Hazard Statement: Heating may cause an explosion.
    • Definition: Propagation of detonation.
    • Symbols: (click image to enlarge), transport: Use appropriate symbol and symbol selection process based on the explosive division (see above)
    • Hazard Category: Type B
    • Signal Word: Danger
    • Hazard Statement: Heating may cause fire of explosion.
    • Definition: Detonation in the package.
    • Symbols: hazard: , transport: (click image to enlarge), and enter explosive pictogram using appropriate symbol and symbol selection process based on the explosive division (see above). Note: For Type B, under the UN Recommendations on the Transport of Dangerous Goods, Model Regulations, special provision 181 may apply (Exemption of explosive label with competent authority approval. See Chapter 3.3 of UN Model Regulations for more details).
    • Hazard Category: Type C
    • Signal Word: Danger
    • Hazard Statement: Heating may cause a fire.
    • Definition: Propagation of deflagration.
    • Symbols: , transport: (click image to enlarge)
    • Hazard Category: Type D
    • Signal Word: Danger
    • Hazard Statement: Heating may cause a fire.
    • Definition: Rapid deflagration in the package.
    • Symbols: , transport: (click image to enlarge)
    • Hazard Category: Type E
    • Signal Word: Warning
    • Hazard Statement: Heating may cause a fire.
    • Definition: Effect of heating under confinement.
    • Symbols: , transport: (click image to enlarge)
    • Hazard Category: Type F
    • Signal Word: Warning
    • Hazard Statement: Heating may cause a fire.
    • Definition: Explosive power.
    • Symbols: , transport: (click image to enlarge)
    • Hazard Category: Type G
    • Signal Word: n/a
    • Hazard Statement: n/a
    • Definition: Thermal explosion in the package.
    • Symbols: n/a


    Physical Hazard: Corrosive to Metals
    Definition: Will materially damage, or even destroy, metals.

    • Hazard Category: Category 1
    • Signal Word: Warning
    • Hazard Statement: May be corrosive to metals.
    • Symbols: hazard: , transport: (click image to enlarge)


    Bibliography:
    Explosives information:
    UN/GHS-SC/a/INF.10 [UN/SCETDG/19/INF.46]. UNECE. 2-6 July 2001. http://www.unece.org/trans/doc/2001/ac10c4/ST-SG-AC10-C4-1-inf10.pdf

    Physical Hazard information:
    Globally Harmonized System of Classification. Third Revised Edition. Annex I: Allocation of Label Elements. UNECE. 2009. http://www.unece.org/trans/danger/publi/ghs/ghs_rev03/English/02e_part2.pdf

    Transport information:
    Globally Harmonized System of Classification. First Revised Edition. Annex 1: Allocation of Label Elements. ST/SG/AC.10/30/Rev.1 UNECE. 2005. http://www.unece.org/trans/danger/publi/ghs/ghs_rev01/English/05e_annex1.pdf

    A Guide to The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) OSHA. 2006, September 11. http://www.osha.gov/dsg/hazcom/ghs.html