Why Do Pen Caps Have a Hole?
Pen caps cover the tips of ballpoint pens, markers, and highlighters found in offices, schools, and homes. The small hole at the top of many caps remains overlooked amid daily use.
This feature addresses a key design requirement in writing instruments.
Historical Origin in Safety Regulations
In the United Kingdom, between 1970 and 1984, nine children died from choking on pen caps.
International Design Standards
The ISO 11540 standard, implemented in 1993 and updated since, requires caps on instruments likely used by children up to age 14 to allow at least 8 liters of airflow per minute if swallowed.
BIC pens incorporate this hole to prevent airway obstruction.
Additional Practical Benefits
The hole also equalizes pressure, aiding ink flow and reducing drying or leakage risks.
Pen caps maintain this hole due to established safety standards and functional efficiency.