I know I'm a bit late to this discussion. I had a similar issue with a polyamide hot melt adhesive. The vendor verified that it was a pure polymer with no additives. Customers kept rejecting it because of the warning.
I emailed IMDS support and got the letter that I attached. In summary, a warning is not grounds for a rejection. The rejection "needs to be clearly motivated on why the cause of the warning is a reason for rejection".
That said, however, I can attest that you will continue to get rejections form many customers any time there is a warning - valid or not. One way to get around the warning is to simple add a small percentage, maybe 1%, as Misc, Not to declare. The data is still technically accurate as there is nothing to prevent the 1% Misc substance from being the same as the 99% reported substance.
