Mercola argues that thimerosal, previously widely used as a vaccine preservative, is harmful.

Unlike other vaccine preservatives used at the time, thiomersal does not reduce the potency of the vaccines that it protects.

Berlanti was instrumental in the pilot's promotion of the theory that a mercury-based vaccine preservative causes autism.

The possible role of a mercury-based vaccine preservative, thimerosal, is still being investigated.

The provision, which no one would claim responsibility for, would have prevented lawsuits by families who say a mercury-based vaccine preservative led to their children's autism.

Among them is Eli Lilly, the developer of thimerosal, a mercury-based vaccine preservative that some parents contend has caused autism in their children.

The litigation industry has used specious theories lacking scientific support to sue vaccine manufacturers for alleged harmful effects caused by vaccines and vaccine preservatives.

Its members primarily blame vaccines, the increase in the number of vaccines administered, and thiomersal, a mercury-based vaccine preservative.

Merthiolate was introduced as a vaccine preservative in 1931, and by the late 1980s thimerosal was used in all whole-cell DPT vaccines.

Ethylmercury is a breakdown product of the antibacteriological agent ethylmercurithiosalicylate, which has been used as a topical antiseptic and a vaccine preservative (further discussed under Thiomersal below).