Arc enemy

Too many people have died from electrocution while working on rooftops. Empower your employees with knowledge and skills to help keep them safe.

Working at heights offers its own unique challenges for employers and workers, not least of all the consideration of electrical safety risks.

Tragically, there have already been multiple electricity-related rooftop deaths this year in Australia and electricians are not the only workers at risk. Builders, carpenters and roofers all need to be aware of electrical safety risks when performing roofing work, like drilling into roofing and cladding materials.

Just last year, a Queensland-based worker unknowingly drilled into an electricity mains cable while installing new metal flashing around a hole in a roof.¹ The resulting electrical arc between the cable and building material left the worker with burns to his hands and forearms — an accident that could have been prevented by a risk assessment, which would have revealed the roof location of the mains cable and switchboard long before any work started.

The reality is that working on or near energised equipment puts all workers at risk of electrical safety hazards. No worksite, from the industrial facility to the high-voltage electrical utility power plant, is exempt, so adopting a total approach to arc flash safety should be a critical component of any employer’s risk management plan.

Arc flash risks

An arc flash occurs when an uncontrolled current passes between two conductors or between a conductor and ground.² The resulting flash is immediate. When voltage is high (anywhere above 300 V), the intense heat of the arc flash can pose a danger to anyone in the arc flash zone. Temperatures can reach more than 19,000°C — four times the temperature of the surface of the sun — which can have devastating effects.³ Workers can be blown from their feet by the flash, or suffer blindness, hearing loss, nerve damage, cardiac arrest, burns and even death. Fire and the release of toxic gases are other electrical risks that must be considered when performing a risk assessment.

Managing electrical risks for employees involves identifying the hazards, assessing the risks and eliminating these risks so far as is reasonably practicable before any work begins. If complete elimination is not possible, which it often is not, especially with roof work, the identified risks must be controlled through measures that remain effective over time. These control measures should be reviewed on an ongoing basis.

Reducing electrical risks

Electrical risks are generally higher if equipment is used outdoors and is portable, which makes electrical connections more vulnerable to damage, putting roof workers at particular risk.

To maintain safe working conditions, electrical equipment should be regularly inspected for damage, wear and electrical faults. Testing must also be carried out to ensure that electrical faults and deterioration invisible to the eye can be detected well before any accidents occur. All electrical equipment used outdoors must also be used with a residual-current device or safety switch, so that the electrical supply will be automatically switched off should electricity leak to earth in quantities harmful to the equipment user.⁴

Given the potential danger to employees working with electricity, employers providing appropriately-rated personal protective equipment (PPE) is critical. All PPE used by the individual, including protective eyewear, insulated gloves, hard hats, aprons and breathing protection, must be able to protect the user from the maximum expected energy levels available at the worksite. Just like any electrical equipment used on site, PPE should regularly be checked and tested for faults and, if any are found, repaired or replaced to ensure its continued efficacy and user safety.

Arc flash explosion. Image credit: Honeywell.

Each piece of PPE should be carefully selected depending on the job it will be used for. If there is chance of high current and arcing, face protection in the form of a face shield might be appropriate. Hard hat/face shield combination kits, designed to protect the entire head, are another option. Eyewear worn must not have metal frames.

Similarly, clothing and footwear worn should be non-conductive and to national safety standards. Appropriately insulated gloves should be worn when conducting any hazardous electrical work. Considerable technological advances have been made to insulated sleeves, which help automate the safety process. RFID-tagged safety sleeves, in partnership with connected worker technologies, help users and managers ensure the PPE is in perfect working order before any hazardous job is begun, taking human error out of the equation.

Educate and empower

Keeping employees safe when working at height also means implementing fall prevention measures. Providing safety education and training to employees regarding PPE use, like how to inspect prior to use and properly fit and wear harnesses, is of the utmost importance. This work, which helps to enforce a strong safety culture, where safety is the priority of both business owner and contractor, is the most valuable employers can do, empowering their workers with the knowledge and skills to look after their safety in the face of the many hazards present on the worksite.

References

1. https://www.worksafe.qld.gov.au/forms-and-resources/newsletter/esafe-newsletters/esafe-editions/esafe/june-2018/be-aware-of-hidden-electrical-cables-on-roofing-and-cladding-jobs
2. https://www.safetyandhealthmagazine.com/articles/13297-hearing-protection-for-arc-flash-hazards
3. https://safety.blr.com/workplace-safety-news/equipment-and-process-safety/electrical-safety/Understanding-arc-flash-hazards/
4. https://www.safeworkaustralia.gov.au/electrical-safety#risks-associated-with-electricity

*Louise Pywell is a Respiratory & Electrical Specialist for Australia & New Zealand for Honeywell Industrial Safety: www.honeywellsafety.com

Image credit: ©stock.adobe.com/au/Sergey Nivens