You are probably familiar with the tiny opening found on most ballpoint pen caps, especially those classic Bic Cristal pens. Whether you're an ardent pen chewer or even just a fanatic fan of writing by hand, most of us have seen it.

It turns out that the purpose it is there has little to do with the pen's function. It was built to fight human carelessness, as Science Alert recently reported.

Though chomping or sucking on a plastic pen cap all day is arguably not practical, not to mention it's not even hygienic, many people do it, particularly children. And that, ultimately, ensures that certain persons wind up eating their pen caps. Businesses such as Bic know this too well because they make ballpen caps that, if they are mistakenly ingested, would not hinder breathing.

This is not just a Bic necessity, but there are especially noticeable gaps in the company's Cristal pens. It is required by the International Organization for Standardization, a federation that sets industrial standards for 161 nations. ISO 11540 says that since pens are to have caps, if they are ingested, they should be built to minimize the chance of asphyxiation.

It relates to writing instruments "which are likely to be used by children up to the age of 14 years in normal or foreseeable circumstances."

Fancy fountain pens and other writing instruments that are specifically intended for adult usage do not need to have gaps in them, nor do caps that are big enough that they can not be swallowed. Every pen that might conceivably find its way into a child's hands ought to provide an air hole in the cap that, according to the standard, allows a minimum flow of 8 liters of air per minute.

100 Years Anniversary Of The Invention of Bakelite
(Photo : Bruno Vincent/Getty Images)
LONDON - MAY 22: A chandelier made out of Bic biro pens is shown at the 100 Years of Plastic exhibition at the Science Museum May 22, 2007 in london. The exhibition is a celebration of plastics timed to coincide with the 100th anniversary of Leo Baekeland?s invention of Bakelite, the world?s first entirely synthetic material.

Can you inhale ink through pen caps?

Pen cap inhalation, particularly for primary school children, is a real risk, although an unusual one. A 2012 study estimated that between 3 and 8% of foreign body aspiration came from pen caps. Foreign body aspiration is the official term for inhaling anything you are not expected to. Another research showed that of 1280 children (aged 6 to 14) hospitalized in Beijing for foreign body inhalation between 1997 and 2007, 34 had inhaled pen caps.

Yet said norms help keep children safe. None of the 34 children died in that Beijing research, and the caps were safely extracted by physicians. That's not always been the case. In the UK, between 1970 and 1984, nine children choked due to swallowing pen caps. The number of fatalities fell precipitously after the UK introduced the universal requirement for air holes in pen caps. Unfortunately, it is not foolproof. In 2007, a 13-year-old in the UK died after mistakenly swallowing his pen cap,

And if you can already breathe into the tiny air hole, it's not an easy feat for doctors to pull a smooth plastic marker cap out of your mouth.

As the case study of 2012 found, the graspers they typically use to take foreign objects out of airways do not always function, and hospitals often have to use multiple tools to get the persistently unstable caps off. The treatment doesn't sound really good. With this, maybe you can avoid the temptation of inserting a pen cap in your mouth.

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