STANDARD FIRST AID TREATMENT FOR CHEMICAL EXPOSURES

Splashes on the skin 
Flood the splashed surface thoroughly with large quantities of running water for ≥10 min or until satisfied that no chemical remains in contact with the skin

Use soap to help remove splashes of solvents, solutions and chemicals known to be insoluble in water

Remove all contaminated clothing, taking care not to contaminate yourself in the process

If necessary, arrange for transport to hospital or refer for medical advice to nearest doctor

Information to accompany the casualty:
Chemical involved
Details of treatment already given
(Special procedures apply to certain chemicals, e.g. anhydrous hydrogen fluoride, aqueous hydrofluoric acid, phenol and related compounds)

Splashes in the eye 
Flood the eye thoroughly with large quantities of clean, cool water or sterile liquid from a sealed container and continue for 10–15 min

Ensure that the water bathes the eyeball by gently prising open the eyelids and keeping them apart until treatment is completed. Do not attempt to remove anything that is embedded

All eye injuries from chemicals require medical advice. Apply an eye pad and arrange transport to hospital

Information to accompany the casualty:
Chemical involved
Details of treatment already given

Inhalation of gas 
Remove the casualty from the danger area after first ensuring your own safety

Loosen clothing; administer oxygen if available
If the casualty is unconscious, place in the recovery position and watch to see if breathing stops

If breathing has stopped, apply artificial respiration by the mouth-to-mouth method; if no pulse is detectable, start cardiac compressions

If necessary, arrange transport to hospital

Information to accompany the casualty:
Gas involved
Details of treatment already given
(Special procedures apply to certain chemicals, e.g. hydrogen cyanide)

Ingestion of poisonous chemical
If the chemical has been confined to the mouth, give large quantities of water as a mouthwash; ensure that the mouthwash is not swallowed

If the chemical has been swallowed, small amounts of water may be administered, more if the chemical is corrosive; administer a specific antidote if one exists

Do not induce vomiting

Arrange transport to hospital

Information to accompany the casualty:
Chemical swallowed
Details of treatment already given
Estimate of quantity/concentration of chemical consumed

CRYOGENICS HAZARD, RISKS AND DANGER BASIC INFORMATION

Cryogenics, or low-temperature technology, is the science of producing and maintaining very low temperatures usually below 120 K, as distinct from traditional refrigeration which covers the temperature range 120 to 273.1 K. At or below 120 K, the permanent gases including argon, helium, hydrogen, methane, oxygen and nitrogen can be liquefied at ambient pressure.

Any object may be cooled to low temperatures by placing it in thermal contact with a suitable liquefied gas held at constant pressure. Applications can be found in food processing, rocket propulsion, microbiology, electronics, medicine, metal working and general laboratory operations.

Cryogenic technology has also been used to produce low-cost, high-purity gases through fractional condensation and distillation. Cryogens are used to enhance the speed of computers and in magnetic resonance imaging to cool high conductivity magnets for non-intrusive body diagnostics. Low-temperature infrared detectors are used in astronomical telescopes.

Typical insulating materials include purged rockwool or perlite, rigid foam such as foam-glass or urethane, or vacuum. However, because perfect insulation is not possible heat leakage occurs and the liquefied gas eventually boils away. Uncontrolled release of a cryogen from storage or during handling must be carefully considered at the design stage. The main hazards with cryogens stem from:

• The low temperature which, if the materials come into contact with the body, can cause severe tissue burns. Flesh may stick fast to cold uninsulated pipes or vessels and tear on attempting to withdraw it. The low temperatures may also cause failure of service materials due to embrittlement; metals can become sensitive to fracture by shock.

• Asphyxiation (except with oxygen) if the cryogen evaporates in a confined space.

• The very large vapour-to-liquid ratios so that a large cloud, with fog, results from loss of liquid.

• Catastrophic failure of containers as cryogen evaporates to cause pressure build-up within the vessel beyond its safe working pressure (e.g. pressures ≤280 000 kPa or 40 600 psi can develop when liquid nitrogen is heated to ambient temperature in a confined space).

• Flammability (e.g. hydrogen, acetylene, methane), toxicity (e.g. carbon dioxide, fluorine), or chemical reactivity (fluorine, oxygen).

• Trace impurities in the feed streams can lead to combination of an oxidant with a flammable material (e.g. acetylene in liquid oxygen, solid oxygen in liquid hydrogen) and precautions must be taken to eliminate them.

• Several materials react with pure oxygen so care in selection of materials in contact with oxygen including cleaning agents is crucial.