HAZMAT Class 4 Flammable solids

Last updated

Flammable solids are any materials in the solid phase of matter that can readily undergo combustion in the presence of a source of ignition under standard circumstances, i.e. without:

Contents

Divisions

Division 4.1: Flammable Solid

Flammable solids are any of the following four types of materials:

  1. Desensitized Explosives: explosives that, when dry, are Explosives of Class 1 other than those of compatibility group A, which are wetted with sufficient water, alcohol, or plasticizer to suppress explosive properties; and are specifically authorized by name either in the 49CFR 172.101 Table or have been assigned a shipping name and hazard class by the Associate Administrator for Hazardous Materials Safety.
  2. Self-Reactive Materials: materials that are thermally unstable and that can undergo a strongly exothermic decomposition even without participation of oxygen (air). Certain exclusions to this group do apply under 49 CFR.
  3. Generic Types: Division 4.1 self-reactive materials are assigned to a generic system consisting of seven types. A self-reactive substance identified by technical name in the Self-Reactive Materials Table in 49CFR 173.224 is assigned to a generic type in accordance with that Table. Self-reactive materials not identified in the Self-Reactive Materials Table in 49CFR 173.224 are assigned to generic types under the procedures of paragraph (a)(2)(iii) of this section.
  4. Readily Combustible Solids: materials that are solids which may cause a fire through friction, such as matches; show a burning rate faster than 2.2 mm (0.087 inches) per second when tested in accordance with UN Manual of Tests and Criteria; or are any metal powders that can be ignited and react over the whole length of a sample in 10 minutes or less, when tested in accordance with UN Manual of Tests and Criteria.
TypeDescription
Type ASelf-reactive material type A is a self-reactive material which, as packaged for transportation, can detonate or deflagrate rapidly. Transportation of type A self-reactive material is forbidden.
Type BSelf-reactive material type B is a self-reactive material which, as packaged for transportation, neither detonates nor deflagrates rapidly, but is liable to undergo a thermal explosion in a package.
Type CSelf-reactive material type C is a self-reactive material which, as packaged for transportation, neither detonates nor deflagrates rapidly and cannot undergo a thermal explosion.
Type DSelf-reactive material type D is a self-reactive material which:
  1. Detonates partially, does not deflagrate rapidly and shows no violent effect when heated under confinement;
  2. Does not detonate at all, deflagrates slowly and shows no violent effect when heated under confinement; or
  3. Does not detonate or deflagrate at all and shows a medium effect when heated under confinement.
Type ESelf-reactive material type E is a self-reactive material which, in laboratory testing, neither detonates nor deflagrates at all and shows only a low or no effect when heated under confinement.
Type FSelf-reactive material type F is a self-reactive material which, in laboratory testing, neither detonates in the cavitated state nor deflagrates at all and shows only a low or no effect when heated under confinement as well as low or no explosive power.
Type GSelf-reactive material type G is a self-reactive material which, in laboratory testing, does not detonate in the cavitated state, will not deflagrate at all, shows no effect when heated under confinement, nor shows any explosive power. A type G self-reactive material is not subject to the requirements of this subchapter for self-reactive material of Division 4.1 provided that it is thermally stable (self-accelerating decomposition temperature is 50 °C (122 °F) or higher for a 50 kg (110 pounds) package). A self-reactive material meeting all characteristics of type G except thermal stability is classed as a type F self-reactive, temperature control material.

Division 4.2: Spontaneously Combustible

Spontaneously combustible material is:

  1. Pyrophoric Material: A pyrophoric material is a liquid or solid that, even in small quantities and without an external ignition source, can ignite within five (5) minutes after coming in contact with air when tested according to the UN Manual of Tests and Criteria.
  2. Self-Heating Material: A self-heating material is a material that, when in contact with air and without an energy supply, is liable to self-heat.

Division 4.3: Dangerous When Wet

Dangerous when wet material is material that, by contact with water, is liable to become spontaneously flammable or to give off flammable or toxic gas at a rate greater than 1 liter per kilogram of the material, per hour, when tested in accordance with the UN Manual of Tests and Criteria. Pure alkali metals are known examples of this.

Placards

UN transport pictogram - 4 (stripes).svg Hazardous Materials
Class 4.1: Flammable Solids
UN transport pictogram - 4 (red).svg Hazardous Materials
Class 4.2: Spontaneously Combustible Solids
UN transport pictogram - 4 (white).svg Hazardous Materials
Class 4.3: Dangerous when Wet

Compatibility Table

Load and Segregation Chart
 Weight1.11.21.31.41.51.62.12.22.22.334.14.24.35.15.26.178
ABA
4.11,001 lb (454 kg)Dark Red x.svgDark Red x.svg  Dark Red x.svg    Dark Red x.svgO      Dark Red x.svg O
4.21,001 lb (454 kg)Dark Red x.svgDark Red x.svgDark Red x.svgODark Red x.svg    Dark Red x.svgO      Dark Red x.svg Dark Red x.svg
4.3Any quantityDark Red x.svgDark Red x.svgDark Red x.svg Dark Red x.svg    Dark Red x.svgO      Dark Red x.svg O
Key
The absence of any hazard class or division or a blank space in the table indicates that no restrictions apply.
  • X: These materials may not be loaded, transported, or stored together in the same transport vehicle or storage facility during the course of transportation.
  • O: Indicates that these materials may not be loaded, transported or stored together in the same transport vehicle or storage facility during the course of transportation, unless separated in a manner that, in the event of leakage from packages under conditions normally incident to transportation, commingling of hazardous materials would not occur.


Source: United States Code of Federal Regulations, Title 49 CFR §177.848 - Segregation of hazardous materials. [1]

Related Research Articles

Explosive Substance that can explode

An explosive is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances.

Hazardous waste

Hazardous waste is waste that has substantial or potential threats to public health or the environment.

An UN number is a four-digit number that identifies hazardous materials, and articles in the framework of international transport. Some hazardous substances have their own UN numbers, while sometimes groups of chemicals or products with similar properties receive a common UN number. A chemical in its solid state may receive a different UN number than the liquid phase if their hazardous properties differ significantly; substances with different levels of purity may also receive different UN numbers.

Oxidizing agent Chemical compound used to oxidize another substance in a chemical reaction

An oxidizing agent, also known as an oxidant or oxidizer, is a substance that has the ability to oxidize other substances — in other words to accept their electrons. Common oxidizing agents are oxygen, hydrogen peroxide and the halogens.

A substance is pyrophoric if it ignites spontaneously in air at or below 54 °C (129 °F) or within 5 minutes after coming into contact with air. Examples are iron sulfide (FeS) and many reactive metals including plutonium and uranium, when powdered or thinly sliced. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or nitrogen. Class D fire extinguishers are designated for use in fires involving pyrophoric materials.

The autoignition temperature or kindling point of a substance is the lowest temperature in which it spontaneously ignites in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical ignites decreases as the pressure is increased.

Tinder Combustible material used to ignite fire by rudimentary methods

Tinder is easily combustible material used to start a fire. Tinder is a finely divided, open material which will begin to glow under a shower of sparks. Air is gently wafted over the glowing tinder until it bursts into flame. The flaming tinder is used to ignite kindling, which in turn is used to ignite the bulk material, to produce a fire.

Dangerous goods Solids, liquids, or gases harmful to people, other organisms, property or the environment

Dangerous goods, abbreviated DG, are substances that when transported are a risk to health, safety, property or the environment. Certain dangerous goods that pose risks even when not being transported are known as hazardous materials.

ADR (treaty) on transport of hazardous materials

ADR, formally the Agreement of 30 September 1957 concerning the International Carriage of Dangerous Goods by Road, is a 1957 United Nations treaty that governs transnational transport of hazardous materials. "ADR" is derived from the French name for the treaty: Accord relatif au transport international des marchandises Dangereuses par Route). Until 31 December 2020, the treaty was fully named European Agreement concerning the International Carriage of Dangerous Goods by Road. However, as the word "European" might have given the impression that the treaty was only open for accession to European states, an amendment was decided in the end of 2019.

Electrical equipment in hazardous areas Electrical equipment in places where fire or explosion hazards may exist

In electrical and safety engineering, hazardous locations are places where fire or explosion hazards may exist. Sources of such hazards include gases, vapors, dust, fibers, and flyings, which are combustible or flammable. Electrical equipment installed in such locations could provide an ignition source, due to electrical arcing, or high temperature. Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations.

Intermediate bulk container

Intermediate bulk containers are industrial-grade containers engineered for the mass handling, transport, and storage of liquids, semi-solids, pastes, or solids. The two main categories of IBC tanks are flexible IBCs and rigid IBCs. Many IBCs are reusable, allowing cleaning and multiple uses.

Globally Harmonized System of Classification and Labelling of Chemicals International standard managed by the United Nations

The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is an internationally agreed-upon standard managed by the United Nations that was set up to replace the assortment of hazardous material classification and labelling schemes previously used around the world. Core elements of the GHS include standardized hazard testing criteria, universal warning pictograms, and harmonized safety data sheets which provide users of dangerous goods with a host of information. The system acts as a complement to the UN Numbered system of regulated hazardous material transport. Implementation is managed through the UN Secretariat. Although adoption has taken time, as of 2017, the system has been enacted to significant extents in most major countries of the world. This includes the European Union, which has implemented the United Nations' GHS into EU law as the CLP Regulation, and United States Occupational Safety and Health Administration standards.

Hazardous Materials Identification System Numerical hazard rating using colour coded labels

The Hazardous Materials Identification System (HMIS) is a numerical hazard rating that incorporates the use of labels with color developed by the American Coatings Association as a compliance aid for the OSHA Hazard Communication (HazCom) Standard.

Potassium nitrate is an oxidizer so storing it near fire hazards or reducing agents should be avoided to minimise risk in case of a fire.

Combustibility and flammability Ability to easily ignite in air at ambient temperatures

A combustible material is something that can burn in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable material catches fire immediately on exposure to flame.

An oxidizer is a chemical that readily yields oxygen in reactions, thereby causing or enhancing combustion.

A flammable liquid is a liquid with flash point of not more than 60.5 °C (141 °F), or any material in a liquid phase with a flash point at or above 37.8 °C (100 °F) that is intentionally heated and offered for transportation or transported at or above its flash point in a bulk packaging.

The HAZMAT Class 2 in United States law includes all gases which are compressed and stored for transportation. Class 2 has three divisions: Flammable, Non-Flammable/Non-Poisonous, and Poisonous. This classification is based on the United Nations' Recommendations on the Transport of Dangerous Goods - Model Regulations. In Canada, the Transportation of Dangerous Goods Regulations, or TDGR, are also based on the UN Model Regulations and contain the same three divisions.

The UN Recommendations on the Transport of Dangerous Goods are contained in the UN Model Regulations prepared by the Subcommittee of Experts on the Transport of Dangerous Goods of the United Nations Economic and Social Council (ECOSOC). They cover the transport of dangerous goods by all modes of transport except by bulk tanker. They are not obligatory or legally binding on individual countries, but have gained a wide degree of international acceptance: they form the basis of several international agreements and many national laws.

Hazardous Materials Transportation Act

The Hazardous Materials Transportation Act (HMTA), enacted in 1975, is the principal federal law in the United States regulating the transportation of hazardous materials. Its purpose is to "protect against the risks to life, property, and the environment that are inherent in the transportation of hazardous material in intrastate, interstate, and foreign commerce" under the authority of the United States Secretary of Transportation.

References

  1. Pipeline and Hazardous Materials Safety Administration (PHMSA) (October 1, 2011). "49 CFR 177.848 - Segregation of hazardous materials" (PDF). Government Publishing Office. p. 853. Archived from the original (PDF) on 16 July 2019. Retrieved 16 July 2019.