Why danger symbols can’t last forever

How to design fear, explained with 99% Invisible. Check them out here: http://99pi.org Correction: The correct spelling of "warning" in Persian is هشدار. Watch the previous episode from this series: http://bit.ly/2DDIQAL Subscribe to our channel! http://goo.gl/0bsAjO Chances are you wouldn't be able to recognize a biohazard even if you were looking right at one.
Gary White