Arc Flash PPE Category 5 in CSA Z462-2021

Background?

The National Standard of Canada for Workplace Electrical Safety is CSA Z462. The 2021 edition of CSA Z462 has been available since January 2021, and the new 2024 edition will be published in only a few short months.

Employers are expected to adopt the new revisions to maintain their compliance. Specifically, anyone with arc flash suits should be aware of the updates to the standard that affect the PPE they use in their daily work tasks.?

Significant Changes to Arc Flash PPE?

Arc flash PPE requirements are updated in every new edition. Up until now, these changes have been minor, such as the requirement to wear an arc-rated balaclava (2012 change). In the 2021 edition there are significant changes including a new Arc Flash PPE Category 5.?

Arc Flash PPE Category Review

Why Did We Need Arc Flash PPE Category 5??

Arc flash PPE is selected so the protection (arc rating) will match or exceed the potential thermal exposure (incident energy) caused by an arc flash incident.

Incident energy is calculated using engineering formulas from the IEEE 1584 Guide. When the IEEE 1584 Guide was updated in 2018, the new formulas resulted in significant changes. In some cases, the incident energy increased by up to 200%.

For example, based on the existing CSA Z462 Table 6a equipment parameters the potential incident energy for 600V switchgear increased from 40 cal/cm2 up to 73 cal/cm2.

This created a critical gap in worker protection because previous editions of CSA Z462 required Category 4 arc flash suits (minimum 40 cal/cm2) for the exact same equipment.

So, to address this issue, the CSA Z462 Technical Committee decided to create a new Category 5 with a minimum 75 cal/cm2 requirement for 600V switchgear.

To harmonize selection methods, the new Category 5 was also used in the new alternative Arc Flash PPE Category selection method (Table V.1).?

Who Does This Impact??

Employers covered by the CSA Z462 scope (Industrial, Institutional, Mining, Airports, Commercial, Construction, etc.) are impacted.

Electrical Utilities (Generation, Transmission & Distribution of electricity) excluded from the scope are indirectly impacted by these changes. Electrical Utilities are expected to follow the ULC S801 Standard, but everyone in Canada uses CSA Z462 for arc flash PPE requirements.?

Caution?

Most arc flash suits on the market are considered Category 4 with arc ratings ranging from 40 - 55 cal/cm2. Work tasks on 600V switchgear are commonly performed in most medium to large size workplaces.

Electrical Workers could be underprotected and at risk of catastrophic skin burn injuries resulting from an arc flash. Many employers will need new Category 5 suits.?

Arc Flash PPE Category 5 Compliance?

Several product options are available with arc ratings ranging from 75 - 140 cal/cm2. The Oberon TCG75 arc flash suit is 76 cal/cm2 with an ultra-lightweight 12.5 oz/yd2 inherently FR fabric system.

For more information on Category 5 and how this will affect you or your team's PPE use and requirements, please reach out to Oberon.