--- In Autism-Mercury@y..., Moria Merriweather <moriam@e...> wrote:
> Hi all,
>
> Okay, this is not a practical question, I don't really have
> to know, but here goes:
>
> I bought contact lens solution yesterday, and read the
> ingredients (just to be sure). Among other things, the
> statement of ingredients says:
> "buffered with tromethamine, tyloxapol as a surfacant,
> and edatate disodium as a chelating agent."
>
> So, um, what does "chelating agent" mean in this context?

A molecule, in this case EDTA, that has more than one binding group in
it for a given target atom. EDTA is an excellent chelating group for
light metals (e. g. calcium, iron) since it has 4-6 binding groups for
them depending on the metal. It will tie them up so that there are no
metals available for bacteria to use in their enzymes. Lysol's
germicidal action is in part due to it containing EDTA.

>
> FWIW the next statement after this is:
> "This preparation contains no chlorhexidine, no thimerosal,
> and no other mercury containing ingreedients."
>
> I guess the producers of eye and ear drops will have
> to say this for a long long time.
>
>