Should any Aldon product be considered toxic or an allergy problem?
Generally speaking, a sealer, cleaner, or anything else from any manufacturer should be considered harmful and needs to be handled with care per the label directions. If you are allergic to any kind of chemicals, do not use them.
Is an Aldon sealer toxic is actually not the correct question. Yes, any sealer might be considered toxic when it is a liquid. When it is cured, you are only dealing with the solids remaining that do the actual sealing.
Two better questions might be, can the cured solids of an Aldon sealer be transferred to food and ingested? If so, are they harmful?
We have never been informed of any negative effect to a pet or a person before or after our sealers are cured. However, it is always good to be careful and watchful. If any doubt, do not take chances.