Xavax is a brand owned by Hama GmbH & Co KG in Germany. According to the details available by checking the link here on Galaxus to the manufacturer's web site, you can find that the mat is made of silicone. According to commonly available information on the Internet Silicone (often made from food-grade polydimethylsiloxane) does not require PFAS (per- and polyfluoroalkyl substances) for their non-stick or heat-resistant properties. One Reddit user in r/ScienceBasedParenting puts it clearly: “There are no PFAS in silicone products… silicone is already water resistant so it doesn’t need to be coated.” According to analysis from material-testing firm NETZSCH, food-grade silicone like that used in baking mats is stable up to around 230 °C and does not release PFAS or other toxic “forever chemicals” during normal use. Your friend in finding these answers in the future is either https://duckduckgo.com/ or https://www.google.com/ and following the links provided already in the product details.

Hello I have bought some several times and never had a problem with taste or smell

Yes, that's what I use it for.

Yes, it's perfectly smooth.

The mat can withstand temperatures of up to 260°C. It is dishwasher safe.