Using LEDs to Increase Workplace Safety

Australia is already recognised as a world leader in industrial and mining safety standards. In order to move fast towards the target of Zero Harm Policy, we need to understand that accident prevention depends on a series of safety checks. One alone will never achieve the target. Workplaces will need to implement layer upon layer of measures so that if the first layer fails, there will be a second and even third layer as backup.

In all poor visibility conditions such as operating at night or in rainy or cloudy weather, workers can be very difficult to spot. The danger is obvious when vehicles and mobile machines are working nearby. Up to now wearing reflective tapes was the standard solution. Over the last several years LEDs have been increasingly utilised as an important and effective addition to tapes.

The effectiveness of tapes depends on light reflection. But LED as an active light does not rely on incoming to activate it and can reach a much longer distance. The difference is the advantage of active light versus reflective light. In addition, flashing LED lights can be used in different ways to generate a stronger visual effect and it can be used in different colours according to the situation.

Because LED lights are electronic devices, it means the user has to take into consideration aspects such as battery consumption, water resistance, ruggedness, explosion proof. Since every worker is already wearing PPE equipment, why not just add LED technology to his existing equipment and now you have LED PPE.

LEDs For The Head

Mounting an LED beacon to the head is a convenient way for a worker to wear a warning light. Since danger is most likely to come from behind rather than in front, attaching a beacon to the back of the helmet will provide sufficient protection in most situations requiring a less than 100 metre signal range. Most miners in North America wear a mini beacon on their helmets which is battery powered. This provides the perfect safety combination – cap lamp in front for illumination and mini beacon on the back for safety. In situation where danger could come from any direction, 360 degree protection is obviously required and can be provided by an LED strip mounted around the helmet. A battery box powering and controlling the LED strip is attached to the back of the helmet. The battery box can even be transparent, becoming itself a beacon. Danger can also come from above which is common at ports and on construction sites. Since crane operators can only see the ground from an elevated position, clearly an LED lights on workers’ helmets give strong visibility to the crane operator who is normally approximately 80 metres above the ground.

LEDs Worn On The Body

LED strips can be attached to the body in many ways to radically increase visibility. The signally range from LED strips can be up to 300 metres or even further. Strips can be attached on the front, the back and even the side for 360 degree protection. Clearly if LEDs are attached to workwear than protection is achieve with any extra item to wear.

There are two way of attaching LED strips for body protection:

LED Brace

The simplest way is to attach LED strips to a webbing and the webbing to worn over the shoulder and fastened to the waist. This is called an LED Brace or LED Strap or LED Harness. LED strips can also be attached to a tool suspender.

LED Hi-Vis Safety Vest

Hi vis safety workwear for night is a critical piece of PPE. The most popular form of protection is the hi vis safety vest. Clearly if LED strips are attached to workwear protection is achieved without any extra object to wear or carry. The battery box can be placed inside a pocket of the vest to protect it.

Buyers will need to give serious consideration to standard compliance and regulations. Hi vis safety vests must comply with hi vis workwear standards, such as AS/NZS 4602.1 in Australia, ANSI/ISEA107 in America and EN/ISO 20471 in Europe. One example of non-compliance is when LED strips are mounted onto a vest with a fluorescent background. Cover background and covering reflective tapes are two things breaking standards in two ways. The first is when LEDs or strips cover the background area, the vest no longer meets the standard. The second is when LEDs or strips are on the reflective tape, the continuation of the reflective is broken, so the vest no longer meets the standard. This is why LED hi viz safety vests must have the LED strips attached when tested to standard by an accredited laboratory. Users should check the standard on the label and ask for the NATA Test Report. They also need to check for washing instructions as they cannot be machine washed. They could be hand washed. Avoid “no washing” or “washing with wrap only”.

LEDs For Other Parts of the Body

LEDs on protective gloves are not common but do exist. They are used for special applications such as traffic control. Frequent hand movements are more visible at night if LEDs are attached to the gloves.

There are a lot of LED shoes on the market designed for recreation/amusement. They do have a use, making people safer when walking at night.

Features of LEDs

Having made the decision to purchase LED PPE, there are a number of factors you need to consider:

LED Brightness

The higher the brightness level, the further it can be seen from. However, brighter lights are not necessarily more desirable. They can be too distracting and cause glare to others. Buyers need to strike a balance between visibility range and glare.

LED Flashes

LEDs can either be constant, slow flash or fast flash. Constant is the most commonly used. However, flashing makes the LEDs more visible and naturally attracts attention to the wearer. Slow flash is preferred to fast flash as it is more relaxing. Fast flash can feel very intense, so it is more mostly used for strong warnings or urgent dangerous situations, such as in police or rescue operations. Some people still feel slow flash is a bit too strong, so blinking flash is becoming a popular choice, ie a quick flash every few seconds, instead of a 50% on and 50% off slow flash. Blinking is much gentler than slow and fast flash, while still drawing attention to the wearer.

LED Colours

LEDs come in various colours. It is important to choose a colour suitable for your working environment. For example, green and red lights are universally used as traffic lights due to their strong light penetration in all weather conditions. On the other hand, railway workers use white LEDs and avoid red and green, because train drivers can confuse them with railway signals. Mines often choose blue lights for their calming effect and also for their ability to keep workers awake in the dark.

Waterproof

All electronic devices are prone to water ingress. Make sure your LEDs are IP66 if for outdoor use.

Battery Consumption

LEDs are powered by replaceable alkaline batteries. This significantly increase your total cost of ownership. Using low signal strength can reduce battery consumption. The most efficient use of the battery is to flash the light in a low duty cycle. For example, compared to a steady signal, a flashing signal in a 30% duty cycle, can extend the life of the battery by three.

Ex (Explosion-proof) Certificate

If the LED PPE is used in a potentially explosive location, such as, an underground coal mine or a petrochemical environment, the LED PPE must Ex Certified. Most LEDs used for PPE are Intrinsically Safe (I.S.) because they are battery powered by low voltage and current. Suppliers should provide the complete set of documents that specify the approval of the LED PPE product in an Ex-environment. These include certification, test reports and user instructions. Normally an I.S. certificate is only required for an LED warning light, rather than for the whole PPE. For example, for an LED safety vest, the I.S. certificate would only be required in the case of LED strip lights. Users should take into account that the I.S. certificate that gives approval for Ex requirements does not include approval for anti-static, fire-retardance and chemical resistance.

All standard helmets and safety vests must meet the minimum requirements of Australian regulatory WHS standards. LED lights provide an additional layer of safety for obscured vision assistance. This helps prevent accidents. So, is purchasing beacon lights for all helmets worth the investment? Should you buy a $9 budget vest or invest in the premium product for valued workers. It is your choice.