Arc Flash PPE Requirements

This document outlines the conditions under which arc flash Personal Protective Equipment (PPE) is required to protect workers from the hazards associated with arc flash events. It is based on safety regulations, industry best practices, and standards such as CSA Z462 and NFPA 70E.

Arc Flash Risk Assessment

An arc flash risk assessment must be performed to:

• Identify arc flash hazards.
• Determine the likelihood of an arc flash incident and potential injuries.
• Determine the severity of potential injuries.
• Determine necessary protective measures, including PPE.

The assessment should consider factors such as equipment design, overcurrent protection, operating time, equipment condition, and maintenance effectiveness. [4]

General Requirements for Arc Flash PPE

Arc-rated PPE is required when the estimated incident heat energy exceeds 2.0 cal/cm². [9]

The protective equipment must cover the employee's entire body, with exceptions for hands, feet, face, and head under specific conditions. [9]

Selection Methods for Arc Flash PPE

CSA standard Z462 provides two methods for determining the required PPE: [1]

1. Incident energy analysis: This method uses the estimated energy of the arc flash to determine the necessary protection level.
2. Arc flash PPE category method: This method uses an arc flash risk assessment of tasks and equipment to determine if arc flash-rated PPE is required. PPE categories are selected based on working distance, fault current, and fault clearing time.

Only one method should be used at a time when working on the same piece of equipment. [1]

Specific PPE Requirements

Clothing:

The outer layer of clothing must be flame-resistant under the following conditions: [9]

• Exposure to energized circuit parts operating at more than 600 volts.
• Risk of an electric arc igniting flammable material in the work area.
• Risk of molten metal or electric arcs from faulted conductors igniting clothing.
• Estimated incident heat energy exceeds 2.0 cal/cm².

Clothing made from meltable fabrics like acetate, nylon, polyester, and polypropylene should be avoided, as they can adhere to the skin and exacerbate burns. [8]

Undergarments made from these fabrics should also be avoided, even under flame-resistant or arc-rated outer layers. [7]

Hands:

Arc-rated protection is not required for hands when:

• Wearing rubber insulating gloves with protectors.
• Wearing heavy-duty leather work gloves (minimum weight of 407 gm/m² or 12 oz/yd²) if the estimated incident energy does not exceed 14 cal/cm².

Feet:

Arc-rated protection is not required for feet when wearing heavy-duty work shoes or boots. [10]

Head and Face:

Minimum head and face protection requirements vary based on the type of arc and estimated incident energy:

** These ranges assume that employees are wearing hardhats meeting the specifications in $ 1910.135 or $ 1926.100(b)(2), as applicable.*

Exposure	Minimum Head and Face Protection - None*	Minimum Head and Face Protection - Arc-rated faceshield with a minimum rating of 8 cal/cm²*	Minimum Head and Face Protection - Arc-rated hood or faceshield with balaclava
Single-phase, open air	2-8 cal/cm²	9-12 cal/cm²	13 cal/cm² or higher t.
Three-phase	2-4 cal/cm²	5-8 cal/cm²	9 cal/cm² or higher #.

For single-phase arcs in open air, if using an arc-rated faceshield, the arc rating for head and face protection may be 4 cal/cm² less than the estimated incident energy. [6]

Other PPE:

In addition to appropriate clothing and footwear, other PPE items are required when there is a risk of an arc flash incident: [1]

• Hard hat (Class G or E)
• Face shield
• Balaclava or hood
• Safety glasses or goggles
• Heavy-duty leather/arc-rated/rubber insulating gloves
• Hearing protection
• Appropriate footwear

All PPE used must be appropriate for the energy expected if an arc flash occurs. [1]

Qualified Persons

A qualified person is someone trained and knowledgeable in the construction and operation of equipment or work methods, familiar with appropriate techniques, policies, procedures, work permits, PPE, insulating and shielding materials, insulated tools, and test equipment. [1]

Unqualified persons should maintain a safe distance from exposed energized conductors or circuit parts and should not enter the arc flash boundary without appropriate PPE and supervision by a qualified person. [1]

Preventive Measures

Whenever possible, work on de-energized equipment following lockout/tagout procedures. [2]

Other protective measures include: [2]

• Ensuring conductors and circuit parts are in a safe working condition.
• Using lower energy equipment or current energy limiting devices.
• Guarding energized electrical conductors and circuit parts.
• Using arc flash approach boundaries, including barricades.
• Increasing the working distance.
• Using non-contact instruments or procedures where possible.
• Using non-sparking tools.
• Implementing work permits, safe work procedures, and job planning.
• Posting signs alerting of the hazards.

Maintenance

Preventive maintenance should include:

• Regular inspection for wear and tear of insulation, corrosion, poor connections, overheated electrical conductors, excessive pitting of contacts, or excessive moisture, water, or ice on the equipment.
• Regular measurements of critical components.
• Routine inspections of circuit breakers and relays, following manufacturer's instructions or NETA guidelines.
• Following established maintenance requirements, including a parts replacement schedule.
• Keeping electrical drawings current.

Approach Boundaries

Boundaries are used to limit how close workers should be to equipment or circuits, especially during work. [2]

The arc flash boundary is the distance at which a person without PPE may receive a second-degree burn (5 J/cm2 or 1.2 cal/cm2). [3]

There are two types of boundaries: [3]

• Limited approach boundary: The distance a person may approach with appropriate PPE and supervision by a qualified person when a shock hazard exists.
• Restricted approach boundary: The distance only a qualified person may approach when there is an increased likelihood of electric shock.

Boundary distances vary depending on the system (AC or DC), voltage range, and presence of equipment. [3]

Causes of Arc Flash

Arc flashes can be caused by:

• Unintentional tool contact with live parts.
• Tools dropped on the ground creating a spark.
• Equipment failure due to poor maintenance or improper design.
• Use of tools that spark.
• Corrosion of contact surfaces.
• Loose contacts.
• Worn or damaged insulation.
• Dust and condensation on insulating materials.
• Incorrect installation of conductors.
• Incorrect installation of arc-resistant equipment.
• Incorrect work procedures.

The possibility of an arc flash increases with exposed energized conductors or when safe work procedures are not followed. [4]

Dates

The obligation for employers to ensure that each employee exposed to hazards from electric arcs wears the required arc-rated protective equipment commenced April 1, 2015. [5]

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