Physical Hazards of Materials
Physical hazards of materials include engulfment, overpresssuration, & thermal hazards (cryogenic & compound gases).
Englufment is one physical hazard of materials that occurs when an individual becomes submerged or buried in the material. This is mostly common when an individual falls into a container of a material and when an individual in a confined space becomes flooded with said material. This type of physical hazard most commonly involves liquids and solids, but can sometimes involve gases. Where there are confined spaces, or in low areas where the gas vapor density is greater than air, it is possible for oxygen to be displaced and for engulfment to occur.
Grain Engulfment Illustration
Overpressuration is mainly associated with gases or with any materials that may react in ways that can produce large amounts of gas. Containers can become overpressurized from a number of different reasons and may result in structural failure that can be violent and catastrophic. Thermal overpressuration is caused by the increase of ambient temperature around the container and often occurs during fires. The increase in temperature corresponds with the increase of pressure associated with a gas or vapor which can lead to pressures greater than the capability of the container can withstand. Pressure failure can result from a damaged container and/or the container no longer has the strength to withstand the force exerted by the gas. A chemical or biological reaction can generate a gas resulting in an overpressuration incident.
Reaction Hazards
Reaction hazards include fire, fuel requirements (liquid & solid), O2 requirements energy requirements, polymerization hazards, thermal decomposition, health hazards, radioactivity hazards, corrosive hazards, explosion hazards, water-reactivity/incompatibility, and worker protection standards.
Fire is considered a self-sustaining chemical reaction that produces energy in the form of heat and light. In order to obtain a fire, there must be a proper mixture of a fuel, oxidizer, and an energy source (such as a spark or a heat surface). This is often expressed as a fire triangle.
Fire Triangle
Corrosive hazards, known as acids and bases, are considered the most common type of hazardous materials. They are able to harm many metals and even human tissue. This type of reaction hazard is most known for producing a local effect, but can also produce systemic effects and even pulmonary edema by inhalation. Acids are best described as a material that yields a hydrogen ion in water and a base is best described as a material that yields a hydroxide ion. When both are combined, they are neutralized.
Polymerization is a process of combining monomers to form larger polymers. Because a given polymer has a wide distribution of lengths, and are usually identified by their relative weight or density, the process is usually accompanied with heat evolution. The speed of which monomers can be controlled by the addition of a catalyst.
Environmental Hazards
Environmental hazards include bioaccumulating/bioconcentrating, warning properties, and geneology.
Bioaccumulation occurs when toxic materials are ingested or absorbed by a species and are not detoxified or eliminated. As the species continues to absorb the contaminated material, the concentration of the toxins in the body increases. As a creature of higher species consumes a creature of lower species, they assume the toxic burden.
Bioaccumulation Diagram
Material "Geneology" is an addition to interpreting the physical properties, chemical properties, nuclear properties and reactivity of the pure material to find the underlying issues associated with the original production and purification of the material as well as how the material will age.
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