It is completely safe in freezers or microwaves * This baking mat works wonderfully as baking pan liner or as a working surface because of its silicon and fiberglass non-stick surface which makes it very easy to clean * 2 piece set 23.75" X 16.75 and 16.75" X 11.75" * Food safe by FDA and NSF standards and effective from 45-degree f - 475-degree f * Easily cleaned with hot water and soap