From a wikipedia article on hard hats:

In his last book, Managing in the Next Society, management professor Peter Drucker credits Franz Kafka, the writer, for developing the first civilian hard hat, to be used in steel mills, when Kafka was employed at the Worker’s Accident Insurance Institute for the Kingdom of Bohemia (1912). Whether or not Kafka actually invented the hard hat is open to debate, but he apparently was the first bureaucrat and insurer to demand its use by civilians.