In the U.S., the term “medical” doesn’t necessarily designate anything -- as it’s not regulated by the FDA or other governing body. In China, where most medical equipment is manufactured, the government puts strict regulations on “medical” and “non-medical” on many different things, including masks.
What the FDA does regulate in masks mostly comes down to “will this mask protect you from arterial spray?” Everything comes down to blood penetration protection, considering these masks are typically made with surgeons in mind. Is the mask going to prevent blood from entering a surgeon's mouth? Will the mask prevent any germs from the surgeon entering the patient’s body?
Keep in mind that if you see the terms “non-medical” or “does not provide liquid barrier protection” that these masks haven’t been tested or regulated by the FDA. Check out the video for more information on surgical masks as well as fun facts about the average speed of arterial spray.