Hazardous Liquid

Hazardous Liquid

Hazardous liquid means LNG or a liquid that is flammable or toxic.

Liquid is one of the principal states of matter. A liquid is a fluid that has the particles loose and can freely form a distinct surface at the boundaries of its bulk material. The surface is a free surface where the liquid is not constrained by a container.

A liquid's shape is determined by the container it fills. That is to say, liquid particles (normally molecules or clusters of molecules) are free to move about the volume, but they form a discrete surface that may not necessarily be the same as the vessel. The same cannot be said about a gas; it can also be considered a fluid, but it must conform to the shape of the container entirely.

At a temperature below the boiling point, a liquid will evaporate until, if in a closed container, the concentration of the vapors belonging to the liquid reach an equilibrium partial pressure in the gas. Therefore no liquid can exist permanently in a complete vacuum. The surface of the liquid behaves as an elastic membrane in which surface tension appears, allowing the formation of drops and bubbles. Capillarity is another consequence of surface tension. Only liquids can display immiscibility. The most familiar mixture of two immiscible liquids in everyday life is the vegetable oil and water in Italian salad dressing. A familiar set of miscible liquids is water and alcohol. Only liquids display wetting properties. Liquids at their respective boiling point change to gases (except when superheating occurs), and at their freezing points, change to solids (except when supercooling occurs). Even below the boiling point liquid evaporates on the surface. Objects immersed in liquids are subject to the phenomenon of buoyancy, which is also observed in other fluids, but is especially strong in liquids due to their high density. Liquid components in a mixture can often be separated from one another via fractional distillation.

The volume of a quantity of liquid is fixed by its temperature and pressure. Unless this volume exactly matches the volume of the container, (one or more) surfaces are observed. Liquids in a gravitational field, like all fluids, exert pressure on the sides of a container as well as on anything within the liquid itself. This pressure is transmitted in all directions and increases with depth. In the study of fluid dynamics, liquids are often treated as incompressible, especially when studying incompressible flow.

If a liquid is at rest in a uniform gravitational field, the pressure \ p at any point is given by

    \ p=\rho g z

where:

    \ \rho = the density of the liquid (assumed constant)
    \ g = gravity
    \ z = the depth of the point below the surface.

Note that this formula assumes that the pressure at the free surface is zero, and that surface tension effects may be neglected.

Liquids generally expand when heated, and contract when cooled. Water between 0 °C and 4 °C is a notable exception. Liquids have little compressibility : water, for example, does not change its density appreciably unless subjected to pressures on the order of 100 bars.

Examples of everyday liquids besides water are mineral oil and gasoline. There are also mixtures such as milk, blood, and a wide variety of aqueous solutions such as household bleach. Only six elements are liquid at or about room temperature and pressure: mercury (densest liquid), bromine, francium, caesium, gallium and rubidium. In terms of planetary habitability, liquid water is believed to be a necessity for the existence of life.

Liquid measures

Quantities of liquids are commonly measured in units of volume. These include the litre, not an SI unit, and the cubic metre (m³) which is an SI unit.

Simple Summary

Between zero and 100°C, water is a liquid. The higher the temperature, the faster (on average) the molecules move. Molecules in a liquid move faster and slip out of position . Liquids flows because the molecules can move over and around each other. So the liquid has a definite volume, but no definite shape. Instead, it will take on the shape of whatever container it is poured into .

A hazard is a situation that poses a level of threat to life, health, property, or environment. Most hazards are dormant or potential, with only a theoretical risk of harm; however, once a hazard becomes 'active', it can create an emergency situation.

Modes of a Hazard

A hazard is usually used to describe a potentially harmful situation, although not usually the event itself; once the incident has started it is classified as an emergency or incident. There are many modes for a hazard, which include:

    * Dormant - The situation has the potential to be hazardous, but no people, property, or environment is currently affected by this. For instance, a hillside may be unstable, with the potential for a landslide, but there is nothing below or on the hillside that could be affected.
    * Potential - Also known as 'Armed', this is a situation wherein the hazard is in the position to affect persons, property, or environment. This type of hazard is likely to require further risk assessment.
    * Active - The hazard is certain to cause harm, as no intervention is possible before the incident occurs.
    * Mitigated - A potential hazard has been identified, but actions have been taken in order to ensure it does not become an incident. This may not be an absolute guarantee of no risk, but it is likely to have been undertaken to significantly reduce the danger.

Classifying Hazards

By its nature, a hazard involves something that could potentially be harmful to a person's life, health, property, or the environment. There are several methods of classifying a hazard, but most systems use some variation on the factors of Likelihood of the hazard turning into an incident and the Seriousness of the incident if it were to occur.

A common method is to score both likelihood and seriousness on a numerical scale (with the most likely and most serious scoring highest) and multiplying one by the other in order to reach a comparative score.

Risk = Likelihood of Occurrence x Seriousness if incident occurred.

This score can then be used to identify which hazards may need to be mitigated. A low score on likelihood of occurrence may mean that the hazard is dormant, whereas a high score would indicate that it may be an Active hazard.

Causes of hazards

There are many causes, but they can broadly be classified as:

    * Natural - Natural hazards include anything that is caused by a natural process, and can include obvious hazards such as volcanoes to smaller scale hazards such as loose rocks on a hillside
    * Man-made - Hazards created by humans, which includes a huge array of possibilities, probably too many to list, as it includes long-term (and sometimes disputed) effects such as global warming to immediate hazards such as building sites
    * Activity related - Some hazards are created by the undertaking of a certain activity, and the cessation of the activity will negate the risk. This includes hazards such as flying.

There are many types of hazards in our daily lives.

From Wikipedia, the free encyclopedia