Hazardous substances and dangerous goods
Home » Hazards / Risks » Hazardous substances and dangerous goods Hazardous substances are chemicals that can harm human health. While it might be obvious that some substances, such as acids or poisons, can cause harm, some health effects may not be so readily apparent. For example, in some cases dusts or vapours can also be hazardous substances. Substances that cause skin irritation, allergies, cancer, birth defects, genetic mutations, and other health effects are also classified as hazardous substances. Health effects may not be immediate and may occur over a long time period. A hazardous substance may be a simple chemical or it may be a mixture of several chemicals. Chemical hazards are not limited to those substances obtained from a supplier and delivered in a labelled container with an SDS. Industrial processes such as welding or grinding may cause toxic fumes or dusts. Toxic atmospheres, or atmospheres without enough oxygen to sustain life, may develop in confined spaces or inadequately ventilated spaces. Examples of some potentially hazardous substances include:
liquefied petroleum gas
Some hazardous substances are also classified as dangerous goods. Dangerous goods are those substances or articles with an immediate risk to health or safety. This includes physical risks such as flammability or corrosion For a hazardous substance to have an effect it has to make contact with or enter the body – the way this occurs is called a route of entry. The main routes of entry are: swallowing – for example from hand contamination or food contact breathing in (inhalation) of atmospheric contaminants
skin or eye contact – such as contact with dust on surfaces, splashes to the skin or eyes. Some substances are so poisonous that swallowing a small amount will cause harm. Swallowing can occur from airborne dusts and sprays, or during eating or smoking from unwashed hands or contaminated food. There are three basic physical forms:
solids (including dusts, fumes and smoke)
liquids (including mists and vapours)
gases (including vapours).
The physical form of a substance often depends on how it has been generated or how it is being used. Dusts
Dusts are generally formed by grinding, abrasion, or crushing of larger solids. They can be generated by processes such as grinding, sanding or polishing. Examples are asbestos, coal, cotton, wood and wheat dust. Most industrial dusts are capable of being drawn into the human respiratory system (ie breathed in). Whether dust gets into the body depends on the size of the dust particle. The two terms used are inspirable and respirable. Inspirable dust includes larger particles that tend to lodge in the upper respiratory tract. Respirable dusts are tiny particles that become lodged deep in the lungs. Some dusts can also be a fire or explosion hazard. In form of a dust some substances become very reactive. Fumes
Fumes are fine, solid, dust particles that are formed when metal is melted and some of the molten metal turns to vapour (for example by processes such as MIG welding or stick welding). As these metal vapours cool they condense into fumes. Fume particles are so small they can be carried deep into the lungs. A single exposure to the fumes of metals, such as zinc oxide, copper oxide or magnesium oxide, can cause metal fume fever. Metal fume fever has symptoms that are very like a cold or the flu, except that the symptoms often clear up when employees are removed from the area where exposure is occurring. Fumes can arise from molten metals such as in lead baths and metal casting. Welding is particularly hazardous when the metal has coatings such as lead or cadmium. Smoke
This results from the incomplete burning of materials. Smoke consists of soot, liquid droplets and ash. Smoke also...
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