Every year, scores of people get infected with various diseases because they were injected using unsterile and reused syringes. It’s unfortunate but it happens more often than you think. Case in point: according to the World Health Organization, 5% of all new HIV cases, 32% of all Hepatitis B cases, and 40%of Hepatitis C cases are caused by unsafe injections.
Aiming to come up with safer, tamper-proof syringes is Dr. David Swann from the Huddersfield University in England. He designed the ABC Syringe, which comes in a nitrogen-filled pack, that has a special coating of ink in its barrel that turns bright red after 60 seconds of exposure to air. Apparently, the ink absorbs the carbon dioxide from the air, causing the ink to change in color.