rigorous (Adjective). Manifesting, exercising, or favoring rigour; allowing no abatement or mitigation; scrupulously accurate; exact; strict; severe; relentless; as, a rigorous officer of justice; a rigorous execution of law; a rigorous definition or demonstration. rigorous (Adjective). Severe; intense; inclement; as, a rigorous winter.
Polylactic acid or polylactide (PLA, Poly) is a biodegradable thermoplastic aliphatic polyester derived from renewable resources, such as corn starch (in the United States and Canada), tapioca roots, chips or starch (mostly in Asia), or sugarcane (in the rest of the world).eing able to degrade into innocuous lactic acid, PLA is used as medical implants in the form of anchors, screws, plates, pins, rods, and as a mesh. Depending on the exact type used, it breaks down inside the body within 6 months to 2 years.
Bisphenol A (BPA) is an industrial chemical used to make polycarbonate plastic resins, epoxy resins, and other products. Bisphenol A (BPA) is a chemical building block that is used primarily to make polycarbonate plastic and epoxy resins.Polycarbonate plastic is a lightweight, high-performance plastic that possesses a unique balance of toughness, optical clarity, high heat resistance, and excellent electrical resistance.o. According to U.S. Environmental Protection Agency records, bisphenol A (BPA) has not been used as an inert ingredient in pesticide products in the U.S. since at least 1994. BPA's status as an (inert) pesticide ingredient was recently rescinded by EPA, according to the June 11, 1999 Federal Register.