The Silentnight Anti-Allergy Ultimate Mattress Topper is filled with anti-allergy hollowfibre that actively protects your bed from bacteria and dust mites to help prevent allergies. Extra 5cm depth provides ultimate comfort, while the quilted cover with internal walls keeps the anti-allergy filling evenly distributed, ensuring lasting support and a consistently plump feel. Our anti-allergy fibres are approved by the British Allergy Foundation, which means they have the ultimate seal of approval. The mattress topper is also fully machine washable at 40 C which means you can keep your bed feeling fresh and clean for longer. This product contains a biocidal ingredient with anti-bacterial properties that protects against fungal growth. The active ingredient is Dimethyloctadecy (3-(trimethoxysilyl)propyl) ammonium chloride. Silentnight are the UK s most trusted sleep brand with over 75 years experience in creating products for every sleeper.