Determining Colour Temperature for Outside Working Environments

HSE LIGHTING AT WORK GUIDANCE (HG38)

The HSE Lighting at Work Guidance (HG38) explains how lighting contributes to the health and safety of people at work. It states that lighting in the workplace:

• Allows people to notice hazards and assess risks.
• Is suitable for the environment and the type of work.
• Provides sufficient light (illuminance on the task).
• Allows people to see properly and discriminate between colours, to promote safety.
• Does not cause glare, flicker or stroboscopic effects.
• Avoids the effects of veiling reflections.
• Does not result in excessive differences in illuminance within an area or between adjacent areas.
• Is suitable to meet the special needs of individuals.
• Does not pose a health and safety risk itself.
• Is suitably positioned so that it may be properly maintained or replaced and disposed of to ensure safety.
• Includes, when necessary, suitable and safe emergency lighting.

For outside working environments, this is of course most relevant when working at night or in regions with few hours of daylight.

COLOUR TEMPERATURE OF LIGHT

So what does the colour temperature have to do with any of this? Firstly, what do we mean by colour temperature?

When you're looking at a white light, sometimes it looks warm and sometimes it looks cooler. This level of warmth and coolness is known as the colour temperature and is measured on the Kelvin Scale (K).  

Much research has been done on the effects of the colour temperature of lighting on people and many of those effects can be directly related back to the points listed above in the HG38.

MOOD AND PRODUCTIVITY

Research shows that environments with high colour temperature lighting enhance concentration, mood and productivity by supressing melatonin levels and keeping people awake and alert. Conversely, warm lighting induces fatigue and eye strain resulting in reduced efficiency and performance.

ACCURACY

Higher colour temperature highlights detail and defects better than warmer colours, and renders colours more accurately, giving operators a more realistic view of what they are seeing when working in darkness. This is helpful when undertaking detailed work or reading documents for example.

HEALTH AND SAFETY

Finally, high colour temperature also provides better visibility and ultimately creates a safer working environment by reducing the risk of accidents and injury. As well as looking after the health and wellbeing of employees, this also saves companies money due to employees taking less time off due to injury or ill-health.

CHOOSING WORKLAMPS

We recommend using LED worklamps with a colour temperature of 5,500K to 6,500K. LED lighting gives much more flexibility on colour temperature than incandescent, halogen or fluorescent lights, which have a fixed, warmer colour temperature. LEDs are available in a full range of colour temperatures. 

Installing LED worklamps also means that a task that is started in daylight can continue uninterrupted into the evening and night, optimising the productivity of an operation.