Respiratory hazards cause irreparable damage to lungs and airways which can lead to serious illnesses including lung disease and cancer.

There are six main forms of respiratory hazard:

Dust – Formed by the breaking down of solid materials, normally when materials are altered. For example, sanding, cutting, grinding, and brushing.

Mist – Formed by processes that involve atomisation (such as spraying, cleaning, and cutting/grinding using coolants) and consist of tiny liquid droplets, rather like steam in a bathroom.

Fumes – Formed by the vaporisation of a solid material by the application of intense heat. Extremely fine particulates are formed as the fume cools and condenses. Many processes form fume, such as smelting, pouring metals, and many welding applications.

Gas – Gases are like air and behave in the same way. Vapours are the gaseous forms of substances, which normally exist as a solid or liquid at room temperature. These are sometimes incorrectly referred to as fumes.

Vapour – A gaseous state formed by evaporation from substances that are normally either solid or liquid at room temperature. Generally released at room temperature, many industrial processes used in degreasing vaporise particularly quickly once heated.

Oxygen deficiency / enrichment – Atmospheres likely to contain less than 19% oxygen are considered oxygen deficient and require specialist equipment. Certain circumstances where the risk may be oxygen enrichment can lead to explosions and severe impairment of operatives.