Useless fact
Why is there a hole in the cap of a pen?
The small hole in the cap of a ballpoint pen is a safety feature designed to prevent suffocation if the cap is accidentally swallowed.
The small hole at the top of a ballpoint pen cap, most famously seen on the ubiquitous BIC Cristal, is not there to keep the ink fresh or balance air pressure. Instead, it is a lifesaving design feature introduced to reduce the risk of asphyxiation. Young children, as well as adults who mindlessly chew on pen caps, run the risk of accidentally inhaling them. If a cap becomes lodged in the windpipe, the ventilation hole ensures a passage of air, allowing the person to continue breathing while waiting for emergency medical assistance. This safety feature was standardized internationally under ISO 11540 in 1993, which requires writing instruments intended for children under fourteen to have ventilated caps or be too large to swallow. Following this standard, major manufacturers worldwide updated their designs, dramatically reducing the number of choking fatalities associated with pen caps.
Why this is true — The ISO 11540 standard requires writing instrument caps to have ventilation holes to reduce the risk of asphyxiation if inhaled.
Sources
- The real reason why there is a hole in the top of your pen cap The Independent