Andy Wade is correct.
"Arctic" is a broad marketing designation. The BS to which the cable is manufactured matters.
YELLOW Arctic to BS 7919 is 110V only.
- Only be used for 110V power tools and not 300/500V.
YELLOW Sold-As-Arctic can be to BS 6500 and is 300/500V.
- Standard on extension reels from JCB, 1.25mm CSA, "Arctic" written along its length, sold by Argos.
BLUE Sold-As-Arctic should be to BS 6500 and is 300/500V.
- Some extension reel makers do actually use it, commonly used for caravan hookups. They would be better off using H07RNF re permanent hookup in wet weather in conditions where cars, bikes etc trundle about.
Not sure if anything in BS 6500 prevents a super-flexible sheath / same material as BS 7919. It comes down to whether BS 6500 standard actually specifies the sheath composition (GP4 GP8 etc). I have seen reels of yellow sold-as-Arctic to BS 6500 on Ebay, because I returned some in 2010 (in two places the insulated cores bulged out through the sheath).