First, let's explain what USP actually means: The United States Pharmacopeia (USP) is a nongovernmental organization that supports public health by setting the latest standards to ensure the quality of drugs and other medical industry technologies. The group focuses on the pharmaceutical and biotechnology industries. USP sets standards for quality, purity, strength and consistency of pharmaceutical grade related products. These USP standards are published in the United States Pharmacopeia and National Formulary (USP NF).USP Class IV products undergo a series of biological tests. USP Class VI compounds must be made from ingredients with a clear history of biocompatibility to meet the strict hygiene grade requirements for the pharmaceutical industry.

Hygienic products used in the medical and biopharmaceutical fields must be biocompatible and chemically stable. The components in the plastic material can not be precipitated into the liquid medicine or human body, otherwise it will cause toxicity and damage to tissues and organs, and poison human body. So in the United States, USP, as a non-profit organization, relies on experts from around the world to set manufacturing standards for medical devices and other related fields such as dietary supplements, food ingredients, pharmaceuticals, and health products. USP Level 6 medical device testing is the most rigorous test of plastic materials used in medical applications and pipeline products used in biopharmaceutical applications. It is a non-clinical laboratory study that complies with various experimental specifications.

The USP defines six levels of detection, from I to VI (VI is still the most stringent). As a result, some drugmakers find it beneficial to pass a USP VI sanitary grade product, especially if it is a candidate for medical devices. Sanitary grade hoses with Class VI certification are expected to be more likely to produce favourable biocompatibility results.

For products to pass the USP Level VI standard, all testing requirements must be passed in order to show very low toxicity. End users often require compliance with USP Level VI requirements. Compliance testing involves assessing the effects of materials and extractable substances on tissues.