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Lighting Ergonomics
by Francois Burman on March 16th, 2017

THE RISKS ASSOCIATED WITH LIGHTING IN A DIVING BUSINESS
 

Good lighting is important in any business in order to maintain a safe, healthy and productive workspace. This is also true for diving businesses, where poor lighting can have far-reaching consequences.

INTRODUCTION

Inadequate or too much light in the workplace is usually considered to be a discomfort or an irritating situation. As first consideration, it is rarely thought to be a safety hazard.
As a result, management tend to react to complaints, rather than assessing the overall impact on safety, productivity or the occupational health of employees.

This is a general, workplace-related issue, which applies equally to the recreational diving environment, despite the overall perception that diving is a leisure activity rather than a traditional place of work. 

Everyone understands that insufficient or intermittent light, or glare, affects one's mental state. Many diving businesses are located in the tropics, with an emphasis on as much outdoor activity as possible, using the surrounding environment to provide the needed lighting. This is, after all, meant to be an enjoyable and stimulating activity.

The staff, however, often have a stressful or even routine experience of poor lighting. Their needs are very different to those of clients.

Flickering fluorescent tubes are generally considered to be a maintenance issue. Poorly lit areas are just a part of the overall sport-based activity.

In this brief discussion, the effects of poorly-considered lighting and their impact on safety will be highlighted, and the means to assess and address the deficiencies will be suggested.
WHAT ARE THE MOST COMMON LIGHTING PROBLEMS?

Insufficient lighting: Specific tasks, especially those that require good eyesight and an ability to see the finer details, such as small parts, sealing surfaces, contamination or fine print require a minimum degree of light to allow for an effective task to be completed. Then what about a poorly lit staircase when coming in from bright sunlight outside? Or a cramped store with heavy articles or hoses and cables crisscrossing the floors? Clearly these are examples of accidents waiting to happen.

Glare: The tropics and other areas which receive bright sunlight or other sources of glare, such as light reflection off the water, or perhaps off a nearby glass surface, can actually provide too much light or cause staff to be unable to look at the task that needs to be done.

Too much light: Sunlight and occasionally bright spot-lamps will reduce the ability to see. This is especially the case with bright sunlight when trying to see divers floating in the water, or even just below the water. 

Improper contrast: Poorly designed lighting which only allows partial illumination, varying over a surface, may render warning or caution signs confusing if not misleading.

Poorly distributed light: Locally illuminated zones with areas of poor illumination make for potentially hazardous activities.

Flickering: Everyone has experienced a fluorescent tube flickering due to a decaying starter unit or a tube nearing the end of its life. The noise factor as well as the intermittent light make reading and seeing difficult and tiring.
WHY DO WE NEED TO PAY ATTENTION TO LIGHTS?

Firstly, we have a clear safety hazard:
  • Where there is insufficient light, it is difficult to judge:
    • the location, size, mass or shape of objects
    • the speed of moving objects or moving parts on machines or mechanisms
This in turn can lead to unnecessary and unfortunate accidents and injuries.
  • Too much light, including bright sunlight, introduces another safety hazard. It may make it impossible to see what is being worked on, it may cause temporary blindness when moving from the sunlight into a darkened room, or worse yet, it may lead to difficulty in spotting divers in the water for retrieval, or running over them with the boat  
​With insufficient or poor lighting, the quality of work being performed may be affected:
  • Insufficient lighting makes it difficult to do precision work (e.g. accurate adjustments of inter-stage pressures)
  • Any form of critical task is difficult to manage, especially if there is a time constraint
  • Both of these could lead to additional time being needed, mistakes being made and unnecessary repairs or rework being required
  • These affect the productivity of work – a risk to the business's health
We have the occupational health hazard; the often unseen and delayed injury:
  • At the least, eye strain and discomfort
  • Headaches from concentration or compensating for insufficient or flickering light
  • Bad posture from inspecting, examining or just viewing tasks that require good, illuminated visual access
  • “Surfer's eye” (Pterygium), which is a benign growth, caused by excessive exposure to UV radiation (e.g. sunlight), causing persistent redness and discomfort, and eventually affecting vision
  • Long-term effects on both mental health and vision from eye-strain
​HOW MUCH LIGHT DO WE NEED?

This all dependent on:
  • The nature of the work being done – the size and mass of the equipment or parts, how quickly this activity is taking place, and the amount of vision needed
  • The condition and location of the work surfaces – whether these reflect or absorb light
  • The vision of the person doing the work – clearly related to the individual performing the activity
  • The duration of the work, task or activity – related to the associated exposure of a person to such an activity
HOW IS LIGHT MEASURED?

​There are two primary aspects and units of measure that we use when quantifying light:
  • The amount of visible light falling on an area, measured in lux or foot-candles (we think of this illuminance – how much)
  • The amount of light that we can see, measured as the lumen (loosely be described as luminous intensity – how bright)
  • Combined, this computes as 1 lux (or foot-candle) = 1 lumen per measure of area. 1 lux = 1 lumen per m2 or 1 foot-candle = 1 lumen per ft2
  • The unit watt does not relate to either of these units. The unit of power (watt), is a measure of how much energy is needed to produce the light
  • The watt is actually misleading, as two different types of lamps, say the halogen versus the LED, produce vastly different lumens for each watt of energy consumed
WHAT ARE THE RECOMMENDED LEVELS OF LIGHTS FOR AN ACTIVITY?

The amount of light needed, for general work areas, is stated in lux: 

Type of activity - Rec. lux1
Public spaces with dark surroundings - 20-50
Short, temporary exposures - 50-100
Working spaces for occasional visual tasks - 100-200
Visual tasks of high contrast or large scale - 200-500
Visual tasks of medium contrast or small size - 500-1 000
Visual tasks of low contrast or very small size - 1 000-2 000
Visual tasks of low contrast or very small size: prolonged period - 2 000-5 000
Performance of very prolonged and exacting visual tasks - 5 000-10 000
Translating these to the requirements for a diving business, the table might look as follows:

Area of activity - Rec. lux2,3
Passages - 20-50
Changing room, equipment rinsing, retail shop - 100-150
Compressor and filling area, storage rooms, kitchen - 200-500
Training room and offices - 250-500
Workshop - 300-750
Precision/instrument workshop for short periods - 1 000-1 500
Inspection of surfaces or fine work - 1 200-1 500
Fine work (accuracy) for longer periods of time - 1 500-2 000

These are only guidelines; different jurisdictions might well apply requiring stricter compliance to higher levels. However, for the average diving business, based on best practices, these recommendations are sound.
HOW DO WE ILLUMINATE THE VARIOUS AREAS IN THE BUSINESS?

There are four considerations that assist in addressing lighting needs, bearing in mind the nature of (recreational) diving businesses, as well as their locations around the globe.
  • Natural lighting:
    • During the day, as far as is practical, this is the most environmentally and economically sensible option
    • One needs to bear in mind the weather variations
    • Rooms can be designed or modified to include the careful selection of materials (light colours but avoiding reflected glare), correctly oriented and sized windows, and the inclusion of skylights
  • Overhead lighting:
    • Fluorescent and CFL lamps provide the best lux results (amount of light)
    • Incandescent and halogen lamps are more useful for higher lumens (intensity)
    • Mercury or sodium lamps provide coverage over wider areas (outside use)
    • ​LEDs provide some excellent solutions to both amount and intensity of light, while consuming the least amount of power and offering the longest life values… but at a price, of course
  • Reflection:
    • Diving resorts are often located in areas with longer periods of sunshine or at least bright surrounds
    • Careful design and balancing of intensity for reflection off the surfaces of the rooms, furniture and even window blinds may enhance lighting levels with no power requirements
  • Task-specific lighting:
    • Spot lamps, using halogen or LED lamps, focussed on the area where activity will take place, is perhaps preferable to having to increase the lighting in the entire room
MEASURING LEVELS

Where strict regulations are on place, businesses may be forced to make use of external organisations, accredited to provide illumination measurements.

However, as recreational diving is often done in remote places, and compliance with requirements is motivated internally by safety reasons, there are a range of options to determine the lighting levels in the various areas of the business.
  • ​Lighting provided by lamps (including halogen, CFLs, LEDs, fluorescent tubes, sodium and mercury):
    • There are a range of inexpensive but relatively effective lux meters. These are, however, not usually calibrated to national standards
    • Today's smart phones have lux-meter applications: these are not accurate but certainly provide a good, relative measure of light
    • In all cases where light from any lamp is being measured, the actual sensor should not be pointed directly at the lighting fixture
  • Natural lighting:
    • Both application-specific measuring instruments, as well as accepted and published (environmental) levels are used to determine the amount of natural light
    • Direct sunlight can be as high as 100 000 lux
    • Indirect and shaded light can be as low as 300 lux
  • Reflected light:
    • These are more difficult to assess, as they may well vary depending on the surfaces and the angle of entry of either natural light, or even light fixtures
    • Lux meters can be used to determine the ambient amount of light, but one needs to be sure not to measure any direct reflection
SO, HOW DO WE FIX PROBLEMS RELATED TO INADEQUATE OR POOR LIGHTING?

Solutions should be determined within the context of the location of the dive business, awareness of the environment, and the need to be efficient.
  • ​Fixtures and bulbs (globes or lamps):
    • A simple remedy is to clean lamps and fixtures regularly. Open-air and facilities designed to blend in with the environment are prone to accumulating dust and grime
    • Follow manufacturers' recommendations as to when to replace bulbs. Flickering and darkened tubes are clearly a sign that replacement is necessary
    • Change out bulbs for more energy-efficient and environmentally-friendly versions, including CFL and LED lamps
    • If necessary, add lighting fixtures where intensified lighting is needed. One can focus on illuminating only the areas needing additional light
  • Natural lighting:
    • Try to paint internal surfaces with lighter colours and use furniture with lighter-coloured finishes while avoiding surfaces that contribute to glare
    • Keep internal surfaces clean
    • Position these surfaces to avoid glare or being placed in shaded areas
    • Where needed, to reduce glare, use some form of sun filter such as light blinds or window film
  • A few general pointers:
    • Try to avoid placing any lighting fixtures behind work surfaces or areas, as these may generate undesirable shadows
    • Avoid placing or locating any work surfaces so that the staff member either looks directly into a bright lamp, into the sun or into any reflected light or glare
    • Measure your lighting levels regularly so as to optimise on any changes made. A smart phone app may not be accurate, but it can determine an improvement or where the illumination actually gets worse
    • Pay attention to where staff may enter dimly lit areas directly from bright sunshine: either increase illumination in the areas, or at least provide a degree of shading prior to entering these areas to allow the eye to adjust
    • Assess your staff in terms of both symptoms of working in poorly or incorrectly illuminated areas, as well as their productivity. This is usually achieved through regular discussions about the working environment, combined with the encouragement of raising reasonable concerns
    • Provide staff with personal protective equipment, such as effective, polarised sunglasses, to reduce glare and direct sunlight when on the boat, and ensure that these are used
CONCLUDING REMARKS

Inadequate or inappropriate lighting is a lesser-accepted cause of safety concerns, reduced productivity or the occupational health of employees.

Where poor lighting is provided and employees complain, management tends to be reactive, rather than accepting and mitigating the impact this has on the working environment.
Dive businesses located in remote or primitive areas have a disadvantage, perhaps in the total lack of power, unreliable power, alternative energy sources with limited output, or at least, in the access to regular lamp or fixture replacement.

There are both practical and efficient ways to resolve this. Assessment of the situation, maintenance and cleaning of lamps, combined with new technology lamps and use of the natural environmental lighting really only requires an awareness and proactive attention to mitigating this issue.
WHAT ARE THE RECOMMENDED LEVELS OF LIGHTS FOR AN ACTIVITY? REFERENCES (PAGE 28 IN DIGTAL COPY)
  1. Illuminating Engineering Society of North America. 2000. Lighting Handbook, (9):10-132.
  2.  Architecture guidelines — multiple sources 
  3. Sustainability Victoria. 2009. Energy Efficiency: Best Practice Guide: Lighting. [Online]. Available at: http://greenbusiness.ie/wpcontent/uploads/2015/06/SRSB-EM-Best-Practice-Guide-Lighting-2009.pdf  [Accessed: 23 January 2017].
REFERENCES
  • National Optical Astronomy Observatory. n.d. Recommended Light Levels for Outdoor & Indoor Venues. [Online]. Available at: https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf [Accessed: 23 January 2017].
  • Illuminating Engineering Society of North America. 2000. Lighting Handbook, (9):4-1037.
  • General Services Administration. 2003. Facilities Standards (P100): Lighting. [Online]. Available at: http://www.gsa.gov/portal/content/101308 [Accessed: 23 January 2017].
  • Sustainability Victoria. 2009. Energy Efficiency: Best Practice Guide: Lighting. [Online]. Available at: http://greenbusiness.ie/wp-content/uploads/2015/06/SRSB-EM-Best-Practice-Guide-Lighting-2009.pdf [Accessed: 23 January 2017].
  • Richman, E. E. Requirements for Lighting Levels. Pacific Northwest National Laboratory. [Online]. Available at: http://www.lumitronlighting.com/lighting_nowledge/LUX%20LEVEL_usace_Requirements%20for%20Lighting%20Levels.pdf [Accessed: 23 January 2017].
  • The Engineering ToolBox. n.d. Illuminance - Recommended Light Levels. [Online]. Available at: http://www.engineeringtoolbox.com/light-level-rooms-d_708.html [Accessed on 23 January 2017].


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