Calculating total formaldehyde amount from dmdmH and formalin

Abdullah

this is the COA of DMDM hydantoin that says it has ~18% formaldehyde.

So will 0.2% of this preservative have the same amount of total formaldehyde as ~0.1% formalin which is 37% formaldehyde in water?

Bill_Toge

it won't, because the amount of active preservative in the raw material is around 55% - the rest is water, so it would contain the equivalent amount as 0.055% formalin

also, the amount of free formaldehyde is considerably less than than that (1% at most), as the rest of it is bound to the DMDM hydantoin molecule (the two -CH2OH groups attached to the nitrogens) and is only released when microbes attempt to ingest it

so the actual amount of formaldehyde in solution is equivalent to 0.00055% formalin at most

Abdullah

@Bill_Toge thanks for explanation.

One more question.
If in DMDM hydantoin 45% is wayer and ~18% is total formaldehyde, what is the rest of that? And does it function as a strong preservative as the rest of formaldehyde? 

Abdullah

This is the composition of DMDM hydantoin. That is why i said if 0.2% DMDM hydantoin is equivalent to ~0.1% formalin.