Graphic Products, Inc. — Published Articles

Inside The Ups & Downs of Electrical Hazards

September 2, 2011
Written By: Steve Stephenson
Cabeling Business

Look up! Electrical hazards are overhead. Live wires run dangerously close to cranes, drilling rigs, backhoes, dump trucks and tree trimmers.

Electrical hazards are the second leading cause of deaths in the construction industry, killing an average of 143 construction workers each year, according to The Center for Construction Research and Training.

Isn't it time for a renewed call for visible cues to warn us of electrical hazard dangers from up high, down low and both inside and outside our facilities? The DuraLabel, www.DuraLabel.com, family of printers, for example, can print electrical hazard signs and labels for signs and labels that are visible from long distances and in low light.

New to the safety sign and label industry are technically advanced sign and label materials that will hold up for years in all kinds of weather conditions – making them ideal for electrical hazards which may occur in facilities and outdoors. A new puncture-proof, water-proof and mildew resistant fabric-like stock is made to survive extreme outdoor and indoor conditions. Aluminum sign blanks are reflective and highly visible. The sturdy backing gives these signs the proper support when posted on poles, fences and other non-adhesive surfaces.

Proper labeling doesn't just save time and money, it saves lives.

In fact, accidental contact of overhead electrical power lines by mobile equipment is a leading cause of occupational fatalities in the United States, accounting for 20% of on-the-job electrocutions, reported the National Institute for Occupational Safety and Health.

A myriad safety rules and regulations have been established to protect those facing the greatest risks from electrical hazards.

The American National Standards Institute (ANSI) has standards for mobile and locomotive cranes that include operation near overhead power lines and tree care operations that provide safety requirements. Standards address the following issues:

• Consider any overhead wire to be energized unless and until the person owning the line or the utility authorities verify that the line is not energized
• De-energize power lines before work begins, erect insulated barriers to prevent physical contact with the energized lines, or maintain safe clearance between the energized lines and boomed equipment
• Notify line owners before work is performed near power lines
• Post warnings on cranes cautioning the operators to maintain safe clearance between energized power lines and their equipment

It's useful to review common electrical hazard safety signs and pay attention to important OSHA/ANSI safety codes, standards and regulations

Make sure to use the appropriate colors, formats and designs as outlined in OSHA §1910.145. Signs used to identify safety issues should be designed in a specified format to comply.

OSHA and ANSI specify "Safety Alert Symbol" usage for each Safety Sign type. This helps readers clearly identify and associate signs with levels of safety.

There are three categories of label and sign types for which OSHA has specified formatting standards. These are DANGER, CAUTION, and SAFETY. ANSI has established standards for WARNING and NOTICE signs.

The following list breaks each OSHA and ANSI safety level down by sign category and describes usage and format requirements.

----------------DANGER HEADER IMAGE --------------------------

Danger signs indicate an imminently hazardous situation, which will result in death or serious injury.

The word "DANGER" is printed in white letters on a rectangular red background and located at the top of the label or sign. This header should be preceded by the "Danger" Safety Alert Symbol. The base of the symbol shall be on the same horizontal line as the base of the letters used as the header. The height of the safety alert symbol shall be equal to or exceed the height of the header letters. Additional info and safety symbols (pictograms) shall appear on a rectangle, white or black panel. Text should be reversed in either black or white. This panel should be located beneath the colored header stripe.

----------------WARNING HEADER IMAGE --------------------------

Warning signs indicate a potentially hazardous situation which could result in death or serious injury. The word "WARNING" is printed in black letters on a rectangular orange background and located at the top of the label or sign. This header should be preceded by the "Warning" Safety Alert Symbol. The base of the symbol shall be on the same horizontal line as the base of the letters used as the header. The height of the safety alert symbol shall be equal to or exceed the height of the header letters. Additional info and safety symbols (pictograms) shall appear on a rectangle, white or black panel. Text should be reversed in either black or white. For ISO consistency, either "ISO" Safety Alert Symbol (shown at top) may be substituted.

----------------CAUTION HEADER IMAGE --------------------------

Caution signs indicate a potentially hazardous situation which may result in minor or moderate injury. It may also alert unsafe practices where property damage is possible. There is one common designs used for CAUTION signs. The word "CAUTION" is printed in black letters on a rectangular yellow background and located at the top of the label or sign. This header should be preceded by the "Caution" Safety Alert Symbol (shown at top). The base of the symbol shall be on the same horizontal line as the base of the letters used as the header. The height of the safety alert symbol shall be equal to or exceed the height of the header letters. Additional info and safety symbols (pictograms) may appear on a rectangle, white or black panel. Text should be reversed in either black or white. Black text may also be used for additional text on an all yellow sign.

----------------NOTICE HEADER IMAGE --------------------------

Notice signs are used to provide general information important or relevant to a building, area, machine or piece of equipment. The word "NOTICE" is printed in white, italic letters. This header is printed on a rectangular blue background and located at the top of the label or sign. Additional info and safety symbols (pictograms) shall appear on a rectangle, white or black panel. Text should be reversed in either black or white.

----------------SAFETY HEADER IMAGE --------------------------

Safety instructional signs are used where there is a need for general instructions and suggestions concerning safety. Various formats are used for SAFETY signs.

Safety related headers or instructions are printed in white letters, on a rectangular green background and located at the top of a label or sign. The header used for a safety sign can vary. Commonly used headers include:

1. ELECTRICAL HAZARD
2. THINK SAFETY
3. BE CAREFUL

Additional information and safety symbols (pictograms) shall be in black letters and appear on a rectangle, white panel. Safety signs may also have a descriptive header with no additional information.

Look down!

Buried or partially exposed power lines are especially hazardous because they can carry extremely high voltage. It's advisable to check work areas for other forms of electrical equipment including street lights and traffic lights – indicators that underground power lines will be present. Look out for sand, plastic strips or specially marked bricks when excavating, which signal the presence of underground power lines. Plans and maps identifying the location of underground cables can date quickly and underground depths can alter road upgrades or developments. The depth of underground cables can vary from site to site or even on the same property. Underground cables should never be moved or relocated unless authorized. Below are tasks that expose workers to underground power lines.

• A plumber cutting a water pipe when there could be an electric cable next to the pipe
• A fencing contractor digging holes where an electric cable could be buried
• Construction site excavation
• Jackhammers
• Well drilling
• Landscaping
• Trenching for pipes

Look inside!

Perform an electrical hazard analysis to review what types of hazards can develop in a plant. Look for oil and grease or debris that can dissolve or damaged insulated cables. Watch out for loose wires that can cause electrical shorts and unguarded temporary lights that are exposed to energized parts. Use the guidelines in NFPA 70E and IEEE 1584 to identify and assess electrical shock and risks throughout your facility.

Your analysis should address:

• What is the hazard?
• What are the consequences of the hazard?
• What is the probability that something will happen?

Arc Flash and Solar Panel – Other Electrical Hazards

An arc flash occurs when an electrical short-circuit produces a high-energy, high-temperature explosion. These occurrences are known to propel molten metal and other debris through the air, endangering anyone nearby. Explosions of this nature can damage a person's eyesight, hearing and even cause severe burning or death. For more information about extremely hazardous electrical Arc Flash dangers, visit www.arcflash.me.

Although unlikely, fires may originate from solar panels. Inspectors may encounter these photovoltaic (PV) arrays with increasing frequency and may want to be aware of the ways in which an installed PV array may pose a fire hazard to a facility. Conduits leading from PV panels to an inverter may remain live with direct current even after the main service panel has been shut off. Firefighters who accidentally sever live lines are vulnerable to electrical shock. PV systems should be labeled in a clear and systematic manner to ensure that technicians and firefighters can swiftly identify key system elements.

Whether the electrical hazard is found indoors, outdoors, far above our heads or buried deep beneath the ground, these hazards need prominent visibility to ensure safe conditions for those who work with or near power lines, tools and construction vehicles. To warn other employees in the facility of the potential hazard, remember to place signs in the area of live repairs being performed. Compliance with sign and label regulations is an important step in the right direction. Protect your workforce by marking electrical hazards clearly.