Yes, 40 year old Tupperware® is safe. Most Tupperware® products are made from high-density polyethylene (HDPE, or plastic #2), low-density polyethylene (LDPE, or plastic #4) and polypropylene (PP, or plastic #5). These plastics are considered to be the safest plastics for frequent and repeated use. Vintage Tupperware is not bad for you. Tupperware® is constantly updating products with more durable and sustainable materials to be more eco-friendly, such as the Recycline range which is created from returned and defected products, giving plastics a second life.