SDCE Phenolic Yellowing Product Codes:4220: Control Fabric 10x3cm 25 piece pack4222: BHT Free 63 Micron Film 400x200mm 100 piece pack4225: Impregnated Test Papers 50 piece pack4227: Glass Plates 100 x 40 x 3mmTesting Categories: Colour Fastness, Chemical Enquiry As specified in BS EN ISO X18, M&S C20B, Next TM43.