Flame Resistant (FR) Work Shirts & Arc Rated Base Layers

A single FR shirt satisfies the upper-body arc rating requirement when worn as the outermost layer, provided its arc rating meets or exceeds the calculated incident energy for the task. However, NFPA 70E requires full-body coverage — upper and lower body. An FR shirt must be paired with arc-rated FR pants, bib overalls, or coveralls, plus the required face, hand, and head protection for the applicable PPE category.

Additionally, NFPA 70E requires FR shirts to be fully fastened and tucked in — exposed skin between the shirt and pants eliminates that portion of protection.

Most FR shirts in our collection carry arc ratings of 4 to 9 cal/cm², qualifying them for NFPA 70E PPE Category 1 (4+ cal/cm²) or Category 2 (8+ cal/cm²) tasks. These cover the majority of daily electrical maintenance work, including motor control center operations, switchboard work, panel maintenance, and similar tasks.

For higher-energy environments requiring CAT 3 or CAT 4 protection, FR shirts are typically worn as a base layer beneath higher-rated arc flash jackets or coveralls — and the combined system rating (not individual garment ratings) determines overall protection. Always check your site's hazard analysis for the specific requirement.

FR base layer shirts (t-shirts, long-sleeve tees, and henleys) are knit construction, lightweight, and designed primarily for comfort, moisture management, and non-melting compliance when worn under arc-rated outer garments. They carry a lower arc rating individually but contribute to overall system protection when layered.

FR work shirts (woven button-down long-sleeve shirts) are more structured, durable, and worn as a standalone daily-wear garment or outer layer. They are typically 6.5–9 oz fabric weight, feature chest pockets and adjustable cuffs, and carry full NFPA 70E and NFPA 2112 certifications as a complete garment.

100% cotton base layers are permitted under arc-rated outer garments per NFPA 70E — cotton is non-melting. However, polyester, nylon, or synthetic blend undershirts must not be worn under arc-rated FR shirts. Synthetic fabrics melt at arc flash temperatures and can cause severe burns even when covered by an outer FR layer. For maximum performance and comfort, an arc-rated FR t-shirt or moisture-wicking FR base layer is the recommended choice.

For warm-weather comfort, look for lightweight FR shirts in the 5–7 oz fabric weight range. Top options include modacrylic/aramid/lyocell blends (soft, lightweight, inherently FR, with natural moisture management), TenCate Tecasafe® fabrics, and lightweight Nomex® IIIA. Many brands now offer FR shirts with moisture-wicking and anti-odor finishes for extended summer field work. Knit FR t-shirts and henleys generally offer better breathability than woven button-downs for high-activity tasks.

Machine wash warm (up to 140°F/60°C) with standard laundry detergent. Do not use bleach, hydrogen peroxide, fabric softeners, starch, or dryer sheets — all degrade FR performance. Tumble dry low or air dry. Ensure all flammable contaminants (oil, grease) are fully removed before the garment is returned to service — contaminated FR shirts must be dry-cleaned or retired if stains cannot be removed by washing. Always keep shirts fully fastened and tucked in when working in FR-required environments.