Why Is There a Hole on the Tip of a Pen Cap? It Can Actually Save Lives in Emergencies

Pick up a capped ballpoint pen and examine it closely—you'll often notice that the tip of the cap isn't fully sealed but has a small hole deliberately designed. Some believe this hole prevents ink from drying out, while others guess it makes it easier to remove the cap. In reality, this inconspicuous hole is primarily a safety feature intended to reduce the risk of complete airway blockage if the cap is accidentally inhaled into the respiratory tract.

Why Do Ballpoint Pen Caps Have Holes? Reducing the Risk of Complete Airway Obstruction

Many children—and even adults—have the habit of biting or holding pen caps in their mouths. If, while speaking, playing, or suddenly inhaling, someone accidentally inhales the cap, it may become lodged below the throat or in the trachea, blocking airflow to the lungs and potentially causing suffocation in severe cases.

According to ISO 11540, established by the International Organization for Standardization, pen caps on writing instruments that may be used by children aged 14 and under under normal or foreseeable circumstances must incorporate size or ventilation design features to reduce the risk of airway obstruction if inhaled.

Manufacturers can design caps large enough to prevent them from entering the airway, or they can include ventilation structures that allow some airflow even if the cap becomes lodged in the respiratory tract.

The hole in the cap cannot dislodge the cap on its own, nor does it guarantee normal breathing. However, it may reduce the likelihood of complete airway closure, delay the onset of oxygen deprivation, and buy crucial time for emergency response and medical treatment.

Pen Cap Has a Hole—But So Does the Barrel? Different Functions

Some transparent ballpoint pens have a small hole not only on the cap but also on the side of the barrel. However, these two holes serve different purposes.

According to product information released by stationery brand BIC, the hole in the cap of the BIC Cristal ballpoint pen is primarily designed to meet safety standards for pen caps. The hole on the barrel, on the other hand, balances internal and external air pressure, helping ink flow smoothly to the tip and preventing leakage.

In other words, the hole on the cap is mainly related to respiratory safety in case of accidental inhalation, while the hole on the barrel is related to ink flow and pressure balance.

Why Don't Some Ballpoint Pen Caps Have Holes?

Not all ballpoint pen caps are required to have holes.

Safety regulations allow manufacturers to adopt alternative designs. For example, caps can be made large enough to prevent entry into the airway, which also reduces the risk of suffocation if inhaled.

Additionally, ISO 11540 mainly applies to writing instruments likely to be used by children aged 14 and under under normal or foreseeable conditions. High-end pens, luxury fountain pens, technical pens clearly intended for adult use, and temporary protective caps used during ink refill transportation may fall outside the scope of this regulation.

Therefore, the absence of a hole in a pen cap does not necessarily mean the product is unsafe. One must consider cap size, external ventilation structures, intended users, and compliance with relevant safety standards.

Having a Ventilation Hole Doesn't Mean You Can Put the Cap in Your Mouth

Even if a pen cap has a ventilation design, children should never suck, chew, or place it in their mouths. The ventilation hole only reduces the risk of complete airway closure; it cannot prevent the cap from lodging in the trachea and cannot replace emergency care or medical treatment.

If someone appears to be choking but can still speak, breathe, or cough forcefully, encourage them to keep coughing and monitor closely. If the person cannot speak, cough effectively, or breathe, immediately ask someone to call 119 and perform age-appropriate choking first aid.

For adults and children over 1 year old with severe airway obstruction, alternate between 5 back blows and 5 abdominal thrusts until the object is expelled or the person loses consciousness. For infants under 1 year, perform 5 back blows followed by 5 chest thrusts—do not use abdominal thrusts.

If the person loses consciousness, begin CPR immediately and continue until emergency personnel arrive. Only remove the object if it is clearly visible and easily accessible; never blindly insert fingers into the mouth, as this may push the object deeper.