According to Merriam-Webster dictionary Hypoallergenic definition is “having little likelihood of causing an allergic response”.
A hypoallergenic mattress is a specially designed mattress which is supposed to prevent allergies. Usually this type of mattress is tightly sealed to prevent dead skin and body oils from penetrating the mattress and attracting dust mites, along with other microscopic organisms that can cause allergic reactions. It works just like a regular mattress, using a series of materials to create a comfortable sleeping surface. Many hospitals use basic hypoallergenic mattresses to keep their patients healthy. These mattresses may have filling identical to an ordinary mattress, but a thick layer of plastic, latex, or vinyl on the outside that prevents materials outside the mattress from seeping in. More expensive mattresses are fully hypoallergenic, using neutral materials which will not aggravate allergies. A less costly alternative to a hypoallergenic mattress is a mattress wrap, which seals the mattress in a layer of protective material.