{"title":"FR Base Layers","description":"\u003cp dir=\"ltr\"\u003eMost FR workwear programs start at the outer layer. That's too late.\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eWhen arc flash or flash fire occurs, non-FR synthetic base layers — polyester, nylon, spandex — melt against skin, turning a survivable incident into a catastrophic burn injury even when the outer FR garment does its job perfectly. The fix is simple and it starts here.\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eRasco FR base layers are built from \u003cstrong\u003e5 oz FR modacrylic blend\u003c\/strong\u003e — inherently flame resistant, lightweight, and moisture-wicking — in a \u003cstrong\u003eperformance athletic fit\u003c\/strong\u003e that moves with your body rather than bunching under your gear. This isn't camping base layer. It isn't hiking underwear. It's engineered for the job site: slim enough to disappear under your work shirt, protective enough to matter at the skin level, breathable enough to actually prevent heat exhaustion on a 95-degree shift.\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eWith a \u003cstrong\u003e6 cal\/cm² arc rating (ATPV) — CAT 1, meets ASTM F1506\u003c\/strong\u003e, every layer in your FR system is now working for you — from skin to outer shell.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eChoose your base layer:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003e\u003ca href=\"https:\/\/rasco.com\/products\/fr-short-sleeve-base-layer-t-shirt\"\u003eFR Short Sleeve Base Layer\u003c\/a\u003e — $76\u003c\/strong\u003e\u003cbr\u003eMaximum breathability. The hot-weather choice for electrical crews, oilfield workers, and anyone working in summer heat who still needs FR from skin out. Pairs under any FR shirt, coverall, or henley.\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003e\u003ca href=\"https:\/\/rasco.com\/products\/fr-long-sleeve-base-layer-t-shirt\"\u003eFR Long Sleeve Base Layer\u003c\/a\u003e — $88\u003c\/strong\u003e\u003cbr\u003eFull arm coverage. The cold weather layering choice and the year-round option for workers who need FR coverage from wrist to collar at all times. Orange version available for crews with hi-vis visibility requirements.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eWhy FR modacrylic?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eFR cotton is heavy. FR synthetics without the FR treatment melt. Modacrylic is the base layer fiber of choice because it's inherently flame resistant — the protection is in the fiber, not a treatment that washes out — and at 5 oz it's dramatically lighter than FR cotton knit. It wicks moisture the way performance athletic wear does, which is what actually prevents heat exhaustion on long shifts in the sun.\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eThe athletic fit matters too. Traditional base layers run relaxed — they bunch under your work shirt and create pressure points through a 10-hour shift. Rasco's base layers are cut for movement: close to the body, flatlock seams that don't irritate skin, tagless construction. You wear it all day and forget it's there until it matters.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eBuild your complete FR system:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eFR Base Layer (6 cal) → FR Henley or Uniform Shirt (8–10 cal) → FR Hoodie (22 cal) → FR Canvas Jacket (38 cal CAT 3)\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eEvery layer rated. Every layer doing its job.\u003c\/p\u003e\n\u003chr\u003e\n\u003cp dir=\"ltr\"\u003e\u003cstrong\u003eWant more weight and coverage?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp dir=\"ltr\"\u003eFor workers who prefer a heavier FR layer against the skin or want a standalone FR shirt with more substantial fabric:\u003c\/p\u003e\n\u003cul dir=\"ltr\"\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/rasco.com\/products\/henley-t-shirt\"\u003eFR Henley (Men's)\u003c\/a\u003e — 7 oz FR cotton, 8.7 cal CAT 2, $65\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/rasco.com\/products\/womens-henley\"\u003eFR Women's Henley\u003c\/a\u003e — 8.7 cal CAT 2, women's cut, $75\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/rasco.com\/products\/long-sleeve-t-shirt\"\u003eFR Long Sleeve T-Shirt\u003c\/a\u003e — 7 oz FR cotton, standalone or layering option\u003c\/li\u003e\n\u003c\/ul\u003e","products":[{"product_id":"fr-long-sleeve-base-layer-t-shirt","title":"FR Long Sleeve Base Layer T-Shirt","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eFR Long Sleeve Base Layer T-Shirt — The Layer That Matters Most\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eYour outer FR shirt is doing its job. This is what protects you underneath it.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eWhen arc flash or flash fire occurs, non-FR synthetic base layers — polyester, nylon, spandex — melt against skin, turning a survivable incident into a catastrophic burn injury. The fix is simple: an FR base layer that performs at the skin level, so every layer in your system is working for you, not against you.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eBuilt from \u003cstrong\u003e5 oz FR modacrylic blend\u003c\/strong\u003e — the preferred base-layer fiber for FR workwear — it's lightweight, soft, and moisture-wicking enough to wear comfortably all day, with a \u003cstrong\u003e6 cal\/cm² arc rating (ATPV) — CAT 1\u003c\/strong\u003e that meets ASTM F1506. Thin enough to disappear under your work shirt. Warm enough to extend your season. Protective enough to complete your system.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eFeatures:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"ltr\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3 print:block print:space-y-1\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e6 cal\/cm² arc rating (ATPV) — CAT 1, meets ASTM F1506\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e5 oz FR modacrylic blend — inherent FR, lightweight, moisture-wicking\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eLong sleeve — full arm coverage for complete layered protection\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTagless, flatlock seams — worn against skin all day, no irritation\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGray — pairs under any FR uniform shirt or henley\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e\n\u003cstrong\u003eOrange\u003c\/strong\u003e — visible FR base layer for traffic exposure and emergency response\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSizes S–5XL in both colors\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cstrong\u003eLayering tip:\u003c\/strong\u003e pair with our FR Henley (8.7 cal) or FR Zip Hoodie (22 cal) for a fully compliant FR layered system from skin to outer layer. Prefer short sleeves for hot-weather work? See the \u003ca class=\"underline underline underline-offset-2 decoration-1 decoration-current\/40 hover:decoration-current focus:decoration-current\" href=\"https:\/\/rasco.com\/products\/fr-short-sleeve-base-layer-t-shirt\"\u003eFR Short Sleeve Base Layer T-Shirt\u003c\/a\u003e →\u003c\/p\u003e\n\u003cp data-crosslinks=\"1\"\u003e\u003cstrong\u003eComplete the kit:\u003c\/strong\u003e \u003ca href=\"\/products\/fr-insulated-duck-bib-overall\" title=\"Rasco FR Insulated Bib Overall\"\u003eFR Insulated Bib Overall\u003c\/a\u003e · \u003ca href=\"\/products\/winter-liner\" title=\"Rasco FR Winter Liner\"\u003eFR Winter Liner\u003c\/a\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eBacked by our \u003ca href=\"https:\/\/rasco.com\/pages\/tough-as-you\" title=\"Rasco FR Tough As You Guarantee\" rel=\"noopener\" target=\"_blank\"\u003eTough As You Guarantee\u003c\/a\u003e.\u003c\/p\u003e","brand":"Rasco FR","offers":[{"title":"Gray \/ S","offer_id":53765410586988,"sku":"FR0542GY-S","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ M","offer_id":53765410619756,"sku":"FR0542GY-M","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ L","offer_id":53765410652524,"sku":"FR0542GY-L","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ XL","offer_id":53765410685292,"sku":"FR0542GY-XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 2XL","offer_id":53765410718060,"sku":"FR0542GY-2XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 3XL","offer_id":53765410750828,"sku":"FR0542GY-3XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 4XL","offer_id":53765410783596,"sku":"FR0542GY-4XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 5XL","offer_id":53765410816364,"sku":"FR0542GY-5XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ S","offer_id":53765410849132,"sku":"FR0542OR-S","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ M","offer_id":53765410881900,"sku":"FR0542OR-M","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ L","offer_id":53765410914668,"sku":"FR0542OR-L","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ XL","offer_id":53765410947436,"sku":"FR0542OR-XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ 2XL","offer_id":53765410980204,"sku":"FR0542OR-2XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ 3XL","offer_id":53765411012972,"sku":"FR0542OR-3XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ 4XL","offer_id":53765411045740,"sku":"FR0542OR-4XL","price":92.0,"currency_code":"USD","in_stock":true},{"title":"Orange \/ 5XL","offer_id":53765411078508,"sku":"FR0542OR-5XL","price":92.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0585\/0500\/3073\/files\/fr-long-sleeve-base-layer-t-shirt-3796775.png?v=1783738567"},{"product_id":"fr-short-sleeve-base-layer-t-shirt","title":"FR Short Sleeve Base Layer T-Shirt","description":"\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eFR Short Sleeve Base Layer T-Shirt — FR Protection at the Skin Level, Built for Heat\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eYour outer FR shirt is doing its job. This is what protects you underneath it.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eWhen arc flash or flash fire occurs, non-FR synthetic base layers — polyester, nylon, spandex — melt against skin, turning a survivable incident into a catastrophic burn injury. The fix is simple: an FR base layer that performs at the skin level, so every layer in your system is working for you, not against you.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eBuilt from \u003cstrong\u003e5 oz FR modacrylic blend\u003c\/strong\u003e — lightweight, soft, and moisture-wicking — with a \u003cstrong\u003e6 cal\/cm² arc rating (ATPV) — CAT 1\u003c\/strong\u003e that meets ASTM F1506. At 5 oz, it disappears under your work shirt. The short sleeve is the hot-weather choice: maximum breathability, zero extra weight, and FR protection from skin out even when it's too hot for long sleeves.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eFeatures:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul dir=\"ltr\" class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3 print:block print:space-y-1\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e6 cal\/cm² arc rating (ATPV) — CAT 1, meets ASTM F1506\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003e5 oz FR modacrylic blend — inherent FR, lightweight, moisture-wicking\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eShort sleeve — maximum breathability for hot-weather work\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eTagless, flatlock seams — worn against skin all day, no irritation\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eGray — pairs under any FR uniform shirt, henley, or coverall\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\"\u003eSizes S–5XL\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003e\u003cstrong\u003eLayering tip:\u003c\/strong\u003e pair with our FR Henley (8.7 cal) for a comfortable, fully FR layered system on hot days — or wear under your FR coverall when you need complete skin-to-outer coverage.\u003c\/p\u003e\n\u003cp data-crosslinks=\"1\"\u003e\u003cstrong\u003eComplete the kit:\u003c\/strong\u003e \u003ca href=\"\/products\/fr-long-sleeve-base-layer-t-shirt\" title=\"Rasco FR Long Sleeve Base Layer T-Shirt\"\u003eFR Long Sleeve Base Layer T-Shirt\u003c\/a\u003e · \u003ca href=\"\/products\/heavyweight-work-shirts-11-5-oz\" title=\"Rasco FR Denim Snap Shirt\"\u003eFR Denim Snap Shirt\u003c\/a\u003e\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" dir=\"ltr\"\u003eBacked by our \u003ca href=\"https:\/\/rasco.com\/pages\/tough-as-you\" target=\"_blank\" title=\"Rasco FR Tough As You Guarantee\" rel=\"noopener\"\u003eTough As You Guarantee\u003c\/a\u003e.\u003c\/p\u003e","brand":"Rasco FR","offers":[{"title":"Gray \/ S","offer_id":53765532746092,"sku":"FR1824GY-S","price":76.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ M","offer_id":53765532778860,"sku":"FR1824GY-M","price":76.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ L","offer_id":53765532811628,"sku":"FR1824GY-L","price":76.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ XL","offer_id":53765532844396,"sku":"FR1824GY-XL","price":76.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 2XL","offer_id":53765532877164,"sku":"FR1824GY-2XL","price":76.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 3XL","offer_id":53765532909932,"sku":"FR1824GY-3XL","price":76.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 4XL","offer_id":53765532942700,"sku":"FR1824GY-4XL","price":76.0,"currency_code":"USD","in_stock":true},{"title":"Gray \/ 5XL","offer_id":53765532975468,"sku":"FR1824GY-5XL","price":76.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0585\/0500\/3073\/files\/fr-short-sleeve-base-layer-t-shirt-9826633.png?v=1783738567"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0585\/0500\/3073\/collections\/Baselayer_Ecomm_Banner.png?v=1789709812","url":"https:\/\/rasco.com\/collections\/fr-base-layers.oembed","provider":"Rasco FR","version":"1.0","type":"link"}