Some non organic rubber mattresses use vanillin. We regard this as a potential health hazard, so true organic crib mattresses don't contain this substance.
Vanillin is used to mainly to give a 'vanilla' flavor to foods, and a vanilla smell to
mattresses.
Originally the vanilla flavor came from the vanilla bean. However, natural vanilla
beans can supply only a tiny fraction of the huge demand for vanilla flavoring.
So artificial vanilla flavoring, or vanillin is used. The problem with artificial vanillin
is that it is made using toxic petroleum based chemicals. One particular
chemical used in the process is a carcinogen called dimethyl sulfate.
Natural latex has a 'rubbery' smell. This is natural, as it comes from the rubber
tree. However in order to make mattresses smell like vanilla, vanillin is added.
This is a potential hazard. Dimethyl sulphate is toxic even in very small
ammounts. While Vanillin is a separate chemical from Dimethyl Sulphate, it is
still a petrochemical.
Petrochemicals may be carcinogens - cancer causing
substances.
So it is not advisable to use vanillin in mattresses, especially infant mattresses.
A study of Dimethyl Sulphate.