Vane Anemometer: See Rotating Vane Anemometer.
		Vapour: Gaseous form of substance which exists as a liquid (usually) under normal conditions.
		Vapour Cloud Explosion: An explosion occurring outdoors beginning with the unplanned release of a large quantity of flammable gas or vapourising liquid which ignites following the formation of a cloud or plume of pre-mixed fuel and air. The speed of flame travelling through the cloud may approach detonation velocity with a massive pressure rise. The over pressure created causes initial damage to property.
		Vapour Density: The ratio of a vapour or gas in relation to air which is taken to have a unitary value.
		Vapour Pressure: The pressure exerted as a proportion of ambient pressure at a specified temperature (normally 20°C).
		VCE: Vapour Cloud Explosion.
		VCM: See Vinyl Chloride Monomer.
		Velocity Pressure: The pressure increase produced by bringing a moving airstream to rest eg as measured by a Pitot-static Tube.
		Velocity Profile: Graphical illustration of the behaviour of air currents around the opening of an LEV hood.
		Ventilation: See Local Exhaust Ventilation and Dilution Ventilation.
		Vibration: Mechanical oscillation produced by regular or irregular movements of a body about its resting position.
		Vibration Dose: Magnitude of vibration x duration of exposure.
		Vibration White Finger: A prescribed disease caused by exposure to vibrating hand held machinery characterised by episodic blanching of the middle or proximal phalanges or the proximal phalanx of the thumb. In this sense, also referred to as secondary Raynaud’s Disease. Vibration causes spasm of peripheral blood vessels.
		Vicarious Liability: Liability of one person for the behaviour of another acting on their behalf. The liability of the employer, for example, for the negligent acts or omissions of their employees acting within the cause and scope of their employment.
		Violations: A deliberate deviation from a rule or procedure which may be routine, situational or exceptional.
		Violence : “Any assault in which an employee is threatened or assaulted by a member of the public in circumstances arising out of the course of his or her employment” HSE.
		Virus: Very small agents containing genetic material and a protein coat. They multiply using the mechanism of a host cell.
		Visual Illusion: See Sensory Illusion.
		Vitiligo: Alterations in skin pigmentation resulting from contact with chemicals eg Quinones which can destroy melanocytes causing patches without pigment
		Volenti Non Fit Injuria: ‘No harm can be done to a willing person’ – a legal phrase used to describe the willing participation of the plaintiff or claimant in the circumstances which led to their injury.
		Volt: Unit of potential difference.
		Voltage: See Pressure.
		Volumetric: Term used to express concentrations of gases and vapours eg parts per million (ppm) (usually at 25oC and 760 mm pressure) - or as a percentage 1,000 ppm = 0.1%.
		VWF: Vibration White Finger.

Disclaimer:
Whilst every effort has been made to ensure the accuracy of the information contained in this book opinions may vary regarding some concepts. The Key Consultancy Ltd and Safety and Health Practitioner accept no responsibility for any loss arising from reliance on this content and readers should take steps to verify interpretations to their own satisfaction if there is doubt.