The first batting helmet officially worn by a team was introduced in 1941, over 20 years after the first hardhat, according to the Baseball Hall of Fame. The first batting helmet was basic, just a cap with plastic panels inside to protect the head. Called the “Brooklyn Safety Helmet," it took time for the helmet to catch on, and many teams refused to wear the hats even as players suffered head injuries. Over time, adoption increased, but the helmet did not become mandatory until 1971.
Hardhats were first introduced in 1919, according to Bullard, with several changes over time to increase safety and reduce weight. According to Incident Prevention, much like the baseball helmet, hardhats took time to catch on. By 1970, hardhats became required PPE across many worksites as part of the Occupational Safety and Health Act, with the same goal of reducing injuries.