Stay safe from the inside out
Most people think flame resistant protection starts and ends with outerwear. Jackets, shirts, and coveralls are the visible gear that get the job done. But real safety begins closer to your skin. What you wear underneath your FR clothing plays a big part in keeping you comfortable and protected all day.
Regular cotton or synthetic underwear can melt, ignite, or stick to your skin when exposed to heat or flame. That’s why FR boxers and underwear are essential. They form the first layer of defense, helping to manage moisture, regulate temperature, and build a stronger FR system from the inside out.
MWG FLEXSAFE™ Men's FR Boxer
Built for long days on the job, the MWG FLEXSAFE™ Men's FR Boxer keeps you comfortable and confident where it counts. Made with inherently flame resistant fabric tested to ASTM 1506-22 and rated ATPV 4.3 cal/cm² (CAT 1), it’s a lightweight FR base layer designed for everyday protection.
The four way stretch fabric moves easily with your body while moisture wicking and odor resistant fibers keep you dry through every task. It feels soft against the skin and performs through long hours in the field. For added protection, layer it under MWG FR pants or bibs and coveralls to strengthen your overall arc rating performance.
MWG FLEXSAFE™ Women's FR Underwear
For years, women in trades have had to settle for unisex gear that never truly fit. The MWG FLEXSAFE™ Women's FR Underwear changes that. Designed with a true women’s fit, it combines softness, breathability, and freedom to move without compromise.
Made from inherently flame resistant fabric, this lightweight base layer stretches in every direction and helps regulate temperature to keep you comfortable and protected on the job. Moisture wicking fibers manage sweat while maintaining a soft feel all day. It is built for women who face the same tough conditions and deserve workwear that fits and performs right.
Why Flame Resistant Base Layers Matter
Every layer adds to your overall protection. FR underwear acts as a thermal barrier that helps reduce burn injuries from flash fires and arc exposure. When combined with outer FR clothing, it strengthens your total ATPV rating, giving you greater protection where layers overlap.
At MWG Apparel, each FR base layer is tested in real world combinations to show how garments perform together. Our layer testing ensures every combination meets safety standards and gives workers the information they need to stay compliant and confident on the job.
We continue to expand our testing results to give you clear data when choosing what to wear for full body protection.
To learn more about how layers work together to keep you safe and compliant, visit our Layering Guide
Built for comfort, performance, and protection
From the job site to the substation, protection begins beneath the surface. The MWG FLEXSAFE™ line of FR underwear for men and women delivers all day comfort and lasting protection, proof that there’s safety in every stitch.