Find numbers in rows (some with multiple numbers) and return header name(s) as answer

Upper Spreadsheet has columns A thru O. Column D thru O have numbers sporadically listed based on the numbers from Column A.

A quick explanation is that the numbers in Column A are EPA chemical numbers. Column D thru Column O are states that place the products as restrictive in their uses. So, not all states will have the same restriction for each of the products. So, some states my not have show a number.

My intention is to have a formula in each cell in Column C that will look across the spreadsheet at each respective row and return to Column C the header state name (CA, CT, MA, MI, etc...), if there is a number listed the cells below it.

The lower spreadsheet example represents how I would like to have Column C return a response to the formula.

Hopefully, I have projected my request properly so that it is understood by anyone who can help me with this.

I have tried Isnumber, isblank and a few other formulas....but nothing came together that would work.

As always, thank you for taking time to assist me with my questions.

How about
IF(D2<>"","Federal",TEXTJOIN(",",1,IF(E2:O2<>"",$E$1:$O$1,"")))

This needs CSE entry, unless you have dynamic arrays.

Thanks for that, pretty sure it needs CSE if you do not have the dynamic array functions, but have no way to check.

Fluff
I applied the formula you suggested and it worked for me without CSE. I am just blown away by this formula becsause I have not heard of "TextJoin" before and now that this has been brought to my attention, I will look for other ways to incorporate this into other possibilities. I really apprecite your taking time to expose this action and formula to me. This will help solve my question I had for this dilema. Thank you both your attention to details. I really appreciate your great work here.

Glad we could help & thanks for the feedback.