Mike Sopp describes how appropriate lighting, that meets Individual requirements, can have a beneficial effect in the workplace and lead to better health as well as reduced costs.
The workplace office has changed considerably over the last 10 years. New technologies such as mobile devices and laptops, innovative use of workspaces and even the demographics of the workforce can all impact on what is required of the office, including the lighting.
The impact of inappropriate office lighting on individuals and employer can be considerable both in terms of the effect on health and increased costs.
Office lighting is usually considered at the design stage of a new build or refurbishment, so the challenge is to ensure that it remains suitable and takes into account evolving workplace tasks and conditions as well as individual needs.
The need for appropriate lighting
According to the Health and Safety Executive (HSE), “poor lighting can not only affect the health of people at work causing symptoms like eyestrain, migraine and headaches, but it is also linked to Sick Building Syndrome (SBS) in new and refurbished buildings”.
For the employer, the consequence of this can be increased absenteeism through ill health and reduced workforce efficiency and productivity.
The need for appropriate lighting is therefore detailed in many pieces of legislation including the various UK Building Regulations and the Health and Safety at Work, etc Act 1974 (HSWA).
In particular, Regulation 8 of the Workplace (Health, Safety and Welfare), Regulations 1992 requires every workplace to have “suitable and sufficient lighting” with the accompanying Approved Code of Practice (ACOP) stating that “lighting should be sufficient to enable people to work, use facilities without experiencing eyestrain, and safely move from place to place”.
Although this requirement sounds straightforward, meeting this goal can be a challenge. The HSE itself notes that “lighting an environment is often a complex task principally considered during the design stage of the building (by architects and interior designers)”.
However, the HSE also notes that “lighting should be designed for the tasks that individuals are carrying out within that environment” and that employers “need to consider any future changes in the work conditions as this may require different lighting design”.
Clearly, where office lighting is considered at the design stage, it should reflect the tasks to be undertaken within that office. The challenge will be to ensure that the lighting requirements remain fit for purpose, should the tasks being undertaken change for example, when new technology is introduced.
The assessment of risk is fundamental to the management of risks and, according to the HSE, this should include “considering whether work lighting arrangements are satisfactory, or whether they pose any significant risks to staff using the workplace”.
HSG38: Lighting at Work provides a good starting point in assessing the overall lighting requirements and whether they are meeting the “suitable and sufficient” criteria, but more detailed guidance may be necessary. The HSE makes reference to Chartered Institution of Building Service Engineer (CIBSE) guidance to assist duty holders in meeting legislative requirements for lighting.
CIBSE produces a series of documents including Society of Lighting publication LG7: Office Lighting. Although primarily aimed at designers of lighting systems, it can assist those responsible for the premises in determining whether lighting is adequate.
As well as detailing the generic approach to office lighting design, the publication contains information as to recommendations for the use of tablets and touchscreens and detailed room design information.
LG7 highlights that “it is important to establish early in the design process if the lighting design is to be based solely on fixed display screens or make provision for handheld and portable devices” but that “where such devices are used, the lighting design can only be effective if it forms part of an overall approach to office management”.
Such management will include accepting that a glare-free environment is not always possible and that, once the design process has commenced, it is difficult to change a design intended for fixed desk use to one that can be used by mobile staff.
The guidance also notes that tablets and smartphones differ from other forms of input and display devices in that they are self-illuminated and thus “there is no requirement to provide a general level of illumination in order for the user to adequately see what they are doing as there is with a traditional keyboard/screen”.
LG7 recommends that typical lighting design for task areas in open-plan offices will be either:
300 lux for mainly screen-based tasks, which can include minor paper-based tasks such as note-taking, or
500 lux for mainly paper-based tasks.
It then gives additional guidance for specific rooms. For example, it notes that for a first aid room, a lux level should be the same as for an open-plan office but suggests that the lighting here generally needs to provide a quiet, attractive ambience, as occupants may be shocked or distressed. There should be adjustable wall or table lights as these may be needed for examination purposes. Quantitative surveys to determine the lux levels can be made in the assessment by use of a light-meter.
According to CIBSE, recent research has revealed that lighting has a clear impact on health and well-being in the workplace and has been shown to affect alertness and accuracy at work.
HSE publication HSG38: Lighting at Work notes that “it is important that employers take into account the needs of individuals when assessing their lighting requirements. This should improve employee comfort and well-being”.
There can be many reasons why an individual has specific lighting requirements, eg the particular task being performed, location of the task, health related eye problems or because of ageing.
A workstation assessment completed in accordance with the Health and Safety (Display Screen Equipment) Regulations is one method that can be used to identify issues.
Measures to minimise problems such as reflection and glares (particularly if using mobile devices) include:
shielding, replacing or repositioning sources of light
rearranging or moving work surfaces, documents or all or parts of workstations
modifying the colour or reflectance of walls, ceilings, furnishings, etc near the workstation or workspace
altering the intensity of vertical to horizontal illuminance.
In general terms, there will be three options available in respect of health or age problems.
Change the optics of the eye so as to provide a sharper retinal image of the task (for example, use spectacles).
Change the task so that the stimuli it presents are higher above threshold (eg magnify or increase font size).
Change the lighting to enhance the capabilities of the visual system (eg increase luminance and/or colour contrast).
The Society of Light and Lighting (SLL) notes that the characteristics of lighting that can produce an improvement in visual performance are the amount of light reaching the retina, the spectrum of the light (for colour discrimination) and the spatial distribution of light (to prevent or reduce shadow and glare). It makes a number of recommendations for improving lighting for older workers in particular including:
using light sources with a Colour Rendering Index (CRI) of more than 80
using luminaires that do not allow a view of the light source from common viewing directions
increasing the minimum maintained illuminance for ambient lighting by 50% above that recommended for the work
in relation to localised task lighting, providing a well shielded, adjustable task light producing an illuminance of at least 1000 lux on the task
in relation to ambient lighting, ensuring the maximum spacing/mounting height ratio of the luminaire has not been exceeded to ensure a high level of illuminance uniformity.
Chartered Institution of Building Service Engineers/Society of Light and Lighting available at www.sll.org.uk.
Providing Visibility for an Ageing Workforce
LG7: Office Lighting
Code for Lighting
Health and Safety Executive available at www.hse.gov.uk.
HSG38: Lighting at Work
L24: Workplace Health, Safety and Welfare. Approved Code of Practice and Guidance
L26: Work with Display Screen Equipment — Guidance on Regulations
Last reviewed 10 March 2016