Is the lace polyester?

I bought this shirt at khols. The label says the fabric is linen and rayon exclusive of decoration. I thought the lace was rayon but now it has been washed it definitely looks like plastic. Any good way to tell without burning it?

Edit: link https://www.kohls.com/product/prd-7944941/petite-simply-vera-vera-wang-long-sleeve-lace-blouse.jsp?color=White%20Knight