The differents toxic, flammable and explosive substances

What are the explosive substances?, How can be classified explosive substances?

Subject: Definition of toxic, flammable and explosive substances

Date:05-Aug-2011 Related Industries:Petrochemical, Chemical, Environmental, Industrial Safety and Personal Protection

Foto por: © Getty Images

Toxic

Add to My Business Files

Send by email

Increase size

Decrease size

In Canada, three lists of hazardous substances have been established. Schedule 1 is a short list that includes high-priority substances commonly found in the country in stationary locations, and those transported in quantities above the thresholds considered in reporting amounts to have a high likelihood of causing accidental death. Schedule 2 is a longer list, and includes the same Schedule 1 substances handled at lower levels, as well as others that in case of sudden release could cause fatalities. Schedule 3 includes other hazardous substances commonly found in Canada but in much smaller quantities and are unlikely to be involved in serious accidents.

Note that there are variations in how the amount of reported or controlled dangerous substances from one country to another, depending on the manner in which the distance between units in the same or different areas of a facility is measured, described as follows:

In the case of U.S. law, a fixed source is the amount of a reported or controlled substance found when the total amount of the substance involved in a process exceeds the threshold or limit.

For purposes of this calculation, a process means any activity that involves the controlled substance and includes any use, storage, manufacturing, handling or movement of the same, or combinations of these activities. It is also considered as a single process when there are multiple physically interconnected containers, or multiple containers close by containing the controlled substance, because in the case of an accident all may be involved in the release of the same substance.

In turn, a stationary source is defined as any building, structure, equipment, facilities or activities of users in a stationary place of regulated substances, which belong to the same company, and are located in one or more contiguous properties, controlled by the same operator and from which there may occur the accidental release of such substances.

In the U.S., the list of controlled substances is based on acute toxicity, accident history and volatility. The values of the control or threshold quantities (TQ) for toxic substances are between 500 and 20,000 pounds. The TQ is set at ten thousand pounds for flammable substances and at five thousand pounds for explosives.

In the case of the Directive of the Council of the European Union (82/501/EEC), the amount of controlled or reported substances refer to each installation or group of installations of the same manufacturer where the distance between them is not enough to avoid, in foreseeable circumstances, an increased risk of serious accidents. Or, the amount refers to each group of installations of the same manufacturer where the distance between them is less than about 500 meters.

In Mexico, according to the General Law of Ecological Equilibrium and Environmental Protection, passed in 1988, the classification of hazardous activities was based on the use of a hazardous substance in quantities that merited its control (known as reported amounts.) Therefore, lists of toxic substances (issued on March 28, 1990) and flammable and explosive substances (on May 4, 1992) were developed and published in the Official Journal of the Federation with their reported amounts.

To determine the threshold amounts for reported substances identified as toxic, the maximum concentration was compared with the maximum permitted levels (doses) to ensure the health and welfare of human beings. Based on the application of mathematical models, there was a simulation of a cloud of gas or vapor released accidentally, through which the maximum concentration of each substance was determined that could be achieved within a certain distance from the source, given stable weather conditions.

The substances included in the lists were selected from various sources, such as those identified by the U.S. Environmental Agency as acutely toxic; lists of substances considered by the General Health Law of the Secretariat of Health; lists of substances that require import permits; as well as substances for which limits have been set for occupational exposure level by the Mexican Ministry of Labor and Social Welfare.

After a comparison between the lists above, it was decided to include all substances that:

- have a IDLH less than 10 mg/m3

- are produced, handled or transported in large volumes in Mexico (including those that are not acute toxic but if released could cause serious problems when considering potential concentration in the environment)

- are found in such quantities that a release, either by leak or spill of the same, would cause the formation of flammable clouds whose concentration would be similar to that of the lower flammable limit in a given area by a band of 100 m in length around the premises or given means of transport

- generate waves of pressure of 1 lb/in2 in a band like the one above in the case of formation of explosive clouds.

Previous 1 2 3 Next

Recommended by the Editor

Definition of toxic, flammable and explosive substances Types of Solvents and their Applications

Sites of Interest

Evonik acquires polymer business from Boehringer Ingelheim GE Capital extends credit to eBioscience Lanxess develops synthetic iron oxide

The differents toxic, flammable and explosive substances

What are the explosive substances?, How can be classified explosive substances?

Subject: Definition of toxic, flammable and explosive substances

Add comments about this article

Comments about this article