100 years DIN A4 formatCurious standards from tea to clay
Tea is quickly made in everyday life. But not when it comes to ISO standard 3103. Here, the process is explained in great detail over six pages. You can read these and other strange guidelines here.
© Patrick Pleul/dpa-Zentralbild/dpa
A nine-year-old girl brushes her teeth with toothpaste. Anyone who follows their dentist's advice will benefit from using it at least twice a day. The tuft extraction test ensures that each individual small tuft of a toothbrush can withstand a force of at least 15 Newtons in accordance with the international standard DIN EN ISO 20126.