What exactly does ANSI mean?
The American National Standards Institute (ANSI) is a private, non-profit organization that administers and coordinates the U.S. voluntary standards and conformity assessment system. The group is made up of industry and government stakeholders that identify and develop standards and conformance–based solutions to national and global priorities.
OSHA in 1970 adopted ANSI sign standard. But in 2011, they introduced the newer version, which features the signal word, pictogram and what the hazard is.