Tested  to

British Standard BS 1877, Part 10: 1997

British Standard BS 7177, 1996 (Low Hazard Domestic Use) 

Choice Of Covers:

Mattress with Mesh cover or Mattress with Quilted Cover.

Both covers are easily removed for washing.

You can also order a fitted 100% cotton sheet - Of course if you order just the sheet, you don't get a mattress you just get the fitted sheet.