When faced with hazardous environments, it’s hard to know what to tackle first. But if you’re handling chemicals that can burn the skin, or using tools that could easily lose you a digit or two, it’s easy to put adequate lighting at the very end of your list of safety priorities. Just to rectify that one now: lighting is pivotal to safety.

Put simply, children aren’t afraid of the dark for no reason. It’s mysterious, unknown, and in the shadows who knows what may be lurking. While I appreciate that may sound a little silly in the context of a child’s bedroom, when in a workplace those shadows could be harbouring anything from sharp objects; to chemicals of which the labels are misread due to poor lighting; to countless slip and trip risks – and all manner of hazards in between.

This article tells the story of one particular site safety analysis in the chemical industry, in which the importance of adequate lighting for worker safety and wellbeing shone through.

Identifying improvements

Once upon a time, our consultants came to a relatively small worksite in the chemical industry for a routine analysis of the existing safety culture. The company was quite well advanced on their journey to good safety culture and needed an external view. We were asked to identify areas of improvements and propose adequate actions. Our method of choice was a multi-step approach comprising inter-alia interviews with the manufacturing team.

Measureable information

In a first step, we systematically collected measurable information on the design of all workplaces like available space, light and noise conditions, as well as necessary functionalities to perform the respective work. The outcome of this part of the analysis was quite satisfactory. The representative of the company was understandably proud, since we could confirm that all objectively identifiable hazards were adequately managed. The workplaces fulfilled all legal requirements and no gaps could be identified.

“even small volumes of flammable liquids, such as 10 litres of a resulting explosive atmosphere are very dangerous in a closed room”

The employer is legally required to analyse the working process, identify and minimise hazards related to the design and use of equipment, handling of chemicals and the context of the workplaces.

Worker interviews

In a second step, we interviewed the workers in order to evaluate the subjective level of satisfaction with the given workplaces. All team members liked their work, but interestingly, we could not reach a consensus in the group regarding the overall satisfaction. It took quite a while until we confined the concern to the situation in a particular building.

Buildings and sub-teams

In the next step, we focused our attention on this building and wanted to meet the respected sub-team. It turned out that there was just one workplace that was held by just one worker. This employee liked his work and classified the workplace as adequate. But he was in quite an annoyed mood and complained about his colleagues, because he missed their willingness to cooperate with him. He was lonely and since no other team member wanted to support him, he needed to work longer than the others. This further isolated him from the team, because he missed the informal information exchange at the end of the working day. Finally, we followed him to his workplace; it was in a warehouse for solvents.

In the ATEX zone

Solvents are very common chemicals used in many different industries and companies. Many solvents are classified flammable and form explosive atmospheres when their vapours are mixed with air. Open handling of flammable liquids may easily turn into a high risk, since even small volumes such as 10 litres of a resulting explosive atmosphere are very dangerous in a closed room. This is why regulators require companies to classify these rooms as ATEX zones and demonstrate a high level of risk management both technically and organisationally. Even more importantly, operations in these areas usually require special permissions and any modifications in equipment require authorisation.

So, we went inside. Our first impression on entering this warehouse was that the inside was rather dark, but it is common sense: an impression is always subjective. The results of the objective measurements were still within the regulatory limits, albeit at the low end.
Scientific work came to the following conclusions:1

Older rooms in ATEX-zones are quite often equipped with only few lights. Another situation that is quite common, is that these lights are even dimmed by dust or dirt that has needed to be cleaned for a long time. Sometimes dark lamps can be found with broken lightbulbs.

When we asked more detailed questions to the warehouse worker, he confirmed that he was satisfied with the workplace as it was, and his tasks carried out therein. That said, we recognised some peculiarities.

We discovered that the only available telephone was from the original days of installation and as such had no caller ID display. The consequence of this detail meant that he could not even recognise a missed call from other team members. While this may seem minor, if a little archaic, it actually further isolated him from the team.

Human beings acquire 80-90% of all information with their eyes. Consequently, light – and especially daylight – is of special importance for humans.1

This worker did not complain or even feel disturbed by the low level of light, he was obviously willing and able to cope with the circumstances, although the situation in the room was definitely not suitable to create a pleasant working atmosphere.

Discussing perceptions

We asked the team to meet again and discussed their perception of the working conditions in this particular working environment. Their statements were unambiguous and very understandable, especially since they matched our own feelings: nobody was willing to work in this dark place – some even described it as a cave.

The lack of support for the lone man was not because of his personality, but because of the perceived darkness in the room. As an interesting side effect, we learnt that there was also a source of permanent noise in the room, which was perceived as annoying by the majority of the team members. Just like the situation with the light, objective measurements demonstrated that the noise level was within the allowed limits, meaning that no physical effect was to be expected, not even a long-term effect. The subjective perception, however, revealed this permanent background noise did in fact cause a distraction from work.

Distribution of light density in a room influences the brightness and how interesting a room is perceived to be. High visual comfort leads to positive working atmosphere and increased motivation, but the effect of light on the atmosphere of work and motivation is quite subjective.1

“are permissions procedures, investment costs, and efforts for maintenance reasons why ATEX areas are often poorly illuminated?”

Proposals and reluctance

The following steps were straight forward: We asked the team to propose a new design for this area. A design, that would make the workplace attractive for everybody. The team came up with the solution of moving the workplace to an outside wall close to a window, allowing in daylight. It included dedicated work place lamps instead of the old ones close to the ceiling. Even new painting of the walls and the floor was proposed. A bright colour was wanted and a modern telephone with a display for easy communication. The solution to extinguishing the annoying noise was provided by the technical department.

The reaction of the management on the request to change the setup in the warehouse was as reluctant as expected.

Safety in ATEX areas is a field that requires particularly specialised experts, and due to the high requirements regarding the installed equipment it is expensive, since:

  • Electrical equipment has the potential to be the most effective ignition source in ATEX zones and needs to be gas-tight to isolate against the surrounding atmosphere
  • As a rule of thumb we know that the price of electrical installation doubles when a non-ATEX area becomes ATEX zone 2 and doubles again for ATEX zone 1
  • Even a simple lamp turns into an expensive piece of equipment if installed in an ATEX zone, but it’s not only the investment that is expensive, maintenance is also more elaborate

Are permissions procedures, investment costs, and efforts for maintenance reasons why ATEX areas are often poorly illuminated?

The reaction of the management is understandable when we consider that high productivity is required to reach a satisfactory payback for such an investment, as well as the inconvenience caused by any nonmanufacturing work in these areas; for example, special precaution measures as a result of a permit to work procedure. And that’s not to mention the need to remove flammables used for production, interrupting work and resulting in a loss of productivity.

Holistic approach

When viewed from an entrepreneurial point of view in the first instance the reluctance becomes understandable. A holistic view, however, goes beyond costs for equipment. An investment to improve the working context can be quite attractive, since the cost of salary might exceed the investment during the life cycle of the installed equipment, and because the working context can strongly contribute to the performance and wellbeing of the employees.

A study showed that increasing brightness from 500 to 600 lx increased the performance by 50%. Bright light has a positive effect on performance and motivation. As a rule of thumb we can notice that the brighter the light, the better sight. That’s up until a certain point, obviously, since blinding leads to discomfort, bad mood and unease. What’s also important to know is that inadequate light levels also have a direct negative effect on quality of work, with low light levels leading to an increase in failure rate.2)


With an argument that included several aspects of productivity, such as overall performance by motivation, failure rate and holiday replacement, the local safety manager was able to convince the management to invest in the workplace.

Light determines the bio rhythm, the orientation and safety of humans and thus is a central design element in architecture. In addition, the location and size of windows needs to be thoroughly considered. Artificial light enables 24/7 work. Consequently, the number, location and brightness of lamps is also very important.

The effect of light on atmosphere and motivation is quite subjective. The psychological impact on humans from the effects of light or noise cannot be measured with technical devices. Nonetheless, scientific work clearly points out that there is an effect on productivity and quality of work.

Our analytical methods go beyond the fulfilment of legal requirements by including the perception of employees. The motivation of human beings is a key enabling factor for business success.

Employees shall have the possibility to influence the design of their workplaces, which is an important factor to enhance productivity.


1 L. Werth, A. Steidle, C. Hubschneider, J. de Boer, K. Sedlbauer: Psychologische Befunde zu Licht und seiner Wirkung auf Menschen – Ein Überblick; Bauphysik 35 (2013), Volume 3; Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co KG, Berlin.

2 Etienne Grandjean, Physiologische Arbeitsgestaltung. Leitfaden der Ergonomie, Landsberg, 4th Ed 1991; ecomed- Storck GmbH