Syringes continue to be re-used around the world because of poverty, mindless people, and often simply by mistake. The ABC Syringe (A Behaviour Changing Syringe) was designed by Dr David Swann, a design professor at University of Huddersfield in the UK, to change color a minute after removing it from its package and warn the user that it’s no longer fresh for use.
The syringe is coated with a special paint that turns red once exposed to CO2, but to prevent it from doing that before use the syringe comes packaged in a nitrogen filled bag, just like your potato chips. Once the bag is opened, the paint is exposed to CO2 and the color changing process begins. About a minute into it, the red becomes quite apparent. The idea has merit, but there are syringes out there that retract the needle following injection and can’t be reused or made to work again.
More from The Guardian: How colour-changing technology could revolutionise the medical industry
(hat tip: Qmed)