Electrical Hazard rated safety boots constitute isolating footwear. They cannot be confused with conductive safety boots such as Static Dissipative boots, which have an entirely different purpose. These boots are made of non-conductive materials that isolate the person’s body from the electrically conductive environment. We will discuss the benefits, the ASTM Tests, and the types of EH boots.
Benefits of EH Boots
There are many risks to a person’s wellbeing from electric contact. Electrocution is one of the most frequent hazards at construction sites. While working with high voltage equipment such as transformers, overhead power lines, conductors, transducers, etc. Electrocution is a daily health and safety hazard that can turn fatal. A worker may be badly burnt, suffer a cardiac arrest, etc. OSHA reports that 300 deaths and 4000 injuries are caused by electrocutions annually. Electricity flows through conductors such as water, metal, earth, and the human body.
When the equipment is working fine, the flow of electricity is maintained between the circuit wires, tools, and source. However, with a malfunction of the circuit or machinery, the worker becomes part of the circuit. This means when in contact the person functions as a conductor, a wire, or a conduit for the current. This current may pass as a tingling sensation, an intense shock, or a cardiac arrest. The severity of the effect depends upon the frequency type, i.e., AC or DC, and its power. The voltages of 120V DC and 50V AC are considered the most hazardous.
These boots serve as a secondary source of protection from electrocution and shocks. The entire surface of the boot is covered in non-conductive material such as rubber. As a result, no electrical charge passes through the body as your body is isolated from the floor. Electrical Hazard (EH) rated boots means that they have been tested by the ASTM using standardized tests. These ASTM-F2412 standardized tests subject the boot to 18000V of AC at 60 Hz for a minute. The outsole is made of polyurethane (PU) or rubber.
Intensity Of Shock And Its Effects
OSHA and ASTM Standards on EH boots
There are many causes of injury by electrocution. The electrocution may occur due to damaged or defective tools. It may be due to incorrectly maintained equipment. It may also be due to improper grounding or/and inadequate wiring. An unsafe work environment with exposed wires or moisture is hazardous.
Unsafe practices such as not wearing Personal Protective Equipment such as EH work boots may cause electrocution. The accidental and unintentional exposition or contact with electric parts too may be a cause. Contact with high-voltage circuits and overhead power-lines may prove fatal. Improper insulation, power surges, and circuit overload are other causes.
OSHA regulation 29 CFR 1910.136(a) expects all workers to wear protective footwear against injuries. These injuries may be from rolling, falling, or sharp objects. These boots offer additional protection due to their Conductive, Static Dissipative, and Electrical Hazard properties. The protective footwear protects from Electrical Hazard (EH) that is they prevent the possibility of electrocution.
They are made of non-conductive materials. Conductive (Cd) footwear grounds static electricity. They are made of materials and cement that offer no or little resistance to the flow of electricity. They prevent the possibility of a static shock or discharge which may cause a fire. Static Dissipative (SD) footwear resists the flow of electricity. Thus the electric charge drifts through the material to be released in a controlled manner to the ground.
ASTM International is a Standards Organization that develops tests, methods, and certifications. These Standards are accepted and observed globally. OSHA mandated standards put forth by ANSI since 1967. These were replaced by ASTM Standards in 2005. ASTM proposed two new standards – ASTM F2413 and F2412 Standard.
The F2413 put forth the Performance Requirements. While the F2412 put forth the test methods that would prove compliance. The boots that comply with the ASTM 2413 – 17 have completely insulated outsoles. These outsoles do not allow the body to come in contact with or function as a conductor. They also provide the added benefit of impact-, compression- and puncture-resistance.
Types of EH boots
There are two types of Electrical Hazard (EH) boots. The steel toe boots and composite toe boots.
Steel Toe Electrical Hazard (EH) boots are made of non-corrosive steel. They may also have a steel puncture-guard plate embedded in the footbed. They are covered with a plastic or rubber coating similar to the ones on the wires. And then housed in non-conductive material for the upper and sole to make them safe around power supplies.
The other feature of steel toe boots is that the toe cap sits on top of the insulting outsole. This prevents contact with the floor. Isolating the person which prevents them from serving as a conducting medium between the electric current and the ground. According to the ASTM F2413-05 Section 5.5.4 & Section 5.5.2, these boots only serve as a secondary source of protection against electrical hazards.
Here is a word of caution, if the steel toe is not covered in the insulating coat or cover. Then any contact between the person and the floor while touching a live wire or circuit will culminate into a shock. In case a person is kneeling and the toe is in touch with the ground, then the circuit between the power system, the person, and the floor is completed via the steel toe. This will result in an electric shock. But there is no need to worry as the Electrical Hazard Footwear with Steel Toes passes the ASTM F2413-17 and 18 tests.
Composite Toe boots are of two types. One with metallic or alloy toes and others with non-metallic toes. The alloy toes may be made of aluminum or titanium, while the non-conductive toes may be made of Kevlar, Carbon fiber, fiberglass, or TPU. All of these are insulating materials.
Titanium is not as hard as steel, it is non-magnetic and a poor conductor of electricity and heat. Aluminum is not as conductive as copper or steel or silver. Besides, it forms an electrically resistive oxide on its surface. This makes it non-conductive or resistive. The boots with composite toes are passed through the same standardized tests as the steel toe ones. Both meet and exceed the expected performance standards.
Their heels and soles are made of non-conductive material that brings shock-resistive properties to the boot. Also, they are poor conductors of heat therefore you are less likely to get hot or frozen toes. They are lighter and spacious. They also pass through metal detectors in security checks on the job site or through airports.
The metallic composite toe boots have caps made of alloys of aluminum or titanium. Aluminum toes are more popular as the alloy is as tough as steel but lighter. These toes are cheaper than titanium toes. Titanium alloy toes are stronger and lighter than steel toes. These boots are 30 to 50 percent lighter than steel toe boots. As these toe caps are thinner, there is more room in the toe box.
What other protection is carried by the Electrical Hazard (EH) Boots?
Electrical Hazard Boots may be waterproof and quick dry. If they are insulating boots, they carry a layer of Thinsulate between the inner and outer layers. The outsole may be non-marking, slip-, abrasion- and oil-resistant.
What are the comfort features of the Electrical Hazard (EH) Boots?
Besides the steel or composite toe, they may be lightweight. They may be very flexible and breathable. The insole and midsole may be made of EVA and foam that mold to the foot and return energy to it. The footbed and outsole may be made of rubber and polyurethane for shock absorption and traction. They can be low-top, mid-top, and high-top boots that may have ankle support.
Are rubber boots sufficient to protect from electric shock?
Yes, rubber boots can protect from electrocution. But it is always safe to use OSHA, ISO, ASTM-Certified Electrical Hazard footwear as they are tested to withstand and protect from such conditions.
What types of work boots are recommended for electricians?
OSHA and ASTM-compliant Electrical Hazard boots are perfect for electricians and engineers who work with power. They are safety rated to withstand up to 18000V at 60Hz. Their soles are made of non-conducting, insulating material.
Working with electricity is inevitable in today’s world. Every construction site, factory floor, or outdoor job requires power tools. This requires electrical circuits and power lines. Thus protection against electrical hazards is essential. OSHA and ASTM Standards enforce federal regulations that make it mandatory for workers to wear protective footwear.
There are two types of footwear that protect against Electrical Hazards. Steel and Composite toe boots are designed by ASTM specifications. They are subjected to Standardized tests by ASTM that test their performance. These tests check the impact-, compression- and puncture-resistance of these boots.
As these boots are made to offer protection against Electrical Hazards, they are tested for these properties. Both – the Steel toe and Composite toe boots meet and exceed the expectations. These boots can withstand 18000V at 60Hz for 1 minute.
|Types of EH boots|
|Composite Toe Boots||Steel Toe Boots|
|Types:||· Alloy/ metallic toe & non-metallic toe
· Alloy toe – made of aluminum or titanium
· Non-metallic – made of Kevlar, TPU, fiberglass, or carbon fiber
|· Metallic toe
· Made of steel
|Sole:||Polyurethane or rubber||Polyurethane or rubber|
|Protection:||· ASTM F2412
· Standard Test Methods for Foot Protection
· Impact test
· Compression test
· ASTM F2413
· Standard Specification for Performance Requirements for Protective (Safety) Toe Cap Footwear
|· Meets both standards
· ASTM F2412 Standard
· ASTM F2413 Standard
|· Boots carry code to indicate protection offer
· Against compression, impact, and puncture
· Additional protection such as
· Metatarsal(Mt), static dissipative(SD), electrical hazard(EH), and puncture protection(PR).
· These boots withstand an impact of 75 foot-pounds
· Compression greater than 2500 pounds.
|· Boots carry a code indicating the protection offered|
|Weather:||· Offer better insulation from the weather due to non-conducting materials||· Steel is an excellent conductor of temperature
· May not offer adequate protection in extreme weather
|Security:||Do not activate off the metal detectors at security checks||Sets off metal detectors|
|Comfort:||· Lighter than steel toes
· Better dexterity and movement
· No strain on the ankle and foot joints
· Less fatigue
|· The weight is due to the gauge of steel in the cap
· The cap is resistant to compression, puncture, and impact