Which class of devices is not subject to regulatory quality system requirements?

Class I devices are generally considered low-risk medical devices and are subject to the least amount of regulatory control compared to higher classes. According to the medical device classification systems, these devices are typically not subject to premarket approval, which involves extensive regulatory quality system requirements. Instead, they may only need to comply with general controls, such as registering the device with the appropriate regulatory authority and adhering to proper labeling and manufacturing practices.

In contrast, Class II and Class III devices carry greater risks and require more stringent regulatory oversight. Class II devices often require a premarket notification, known as a 510(k), demonstrating that they are substantially equivalent to a device already on the market. Class III devices, being the highest risk, necessitate premarket approval (PMA), which involves rigorous review and adherence to comprehensive quality system regulations. As for Class IV, it is not a classification typically recognized in the context of U.S. regulatory systems, which can contribute to confusion, but it is important to focus on the established categories above.

Thus, the distinction lies in the level of regulatory scrutiny and quality system requirements applicable to each class of devices, with Class I being the least regulated under current norms.