Buzz
If you’re someone who loves to chew on pens, or just a fan of handwriting, you’ve probably noticed the tiny hole on top of most ballpoint pen caps, especially on the iconic Bic Cristal pens. Surprisingly, this hole isn’t designed for pen performance. According to Science Alert, it serves a much more critical purpose—protecting against accidental choking.
Though chewing or sucking on a plastic pen cap isn’t recommended—and definitely isn’t the most hygienic habit—many people, especially kids, still do it. And, unfortunately, some end up swallowing the cap. Bic is well aware of this risk, which is why they design their pen caps with holes that ensure airflow in case of an accidental swallow.
This isn’t just a design feature from Bic. In fact, the International Organization for Standardization (ISO), which sets industrial standards across 161 countries, mandates it.
This regulation applies to writing tools that are likely to be used by children up to the age of 14. Fancy fountain pens and other writing instruments clearly meant for adults don't need air holes, nor do large caps that can't be swallowed. However, any pen that might be used by children must have a cap with an air hole that allows a minimum airflow of 8 liters (about 2 gallons) per minute, according to the standard [PDF].
While rare, the danger of inhaling a pen cap is real, particularly for younger children. A 2012 study [PDF] found that pen caps contribute to 3 to 8 percent of cases of “foreign body aspiration,” the medical term for inhaling objects you shouldn’t. Another study noted that of 1280 children (aged 6 to 14) treated for foreign body inhalation in Beijing between 1997 and 2007, 34 had swallowed pen caps.
Fortunately, these standards have helped save lives. In the Beijing study, none of the 34 children died, and doctors successfully removed the caps. However, this wasn’t always the case. In the UK, between 1970 and 1984, nine children suffocated after swallowing pen caps. After the UK implemented the international standard for air holes, the number of deaths dramatically decreased [PDF]. Unfortunately, it’s not perfect; in 2007, a 13-year-old in the UK died after accidentally ingesting a pen cap.
Even if you can still breathe through the air hole, removing a plastic pen cap from your throat is no simple task. The usual tools doctors use to remove foreign bodies from airways don’t always work, as a 2012 case report discovered. Sometimes, hospitals must use alternative tools, like a catheter that works through the hole in the cap and then inflates a small balloon to extract the cap. It's not a pleasant procedure, so it might be wise to avoid putting that pen cap in your mouth.
