Permission is granted to the University of Pennsylvania Law School by the American National Standards Institute (ANSI) to use ANSI Z37.4-1969 for educational purposes only. Please note that ANSI Z37.4-1969 is an outdated and withdrawn standard and is no longer recognized or supported by the American Industrial Hygiene Association (AIHA). The original copyright holder, the United States of America Standards Institute (USASI), is no longer in business. ANSI Z37.4-1969 cannot be referred to as an American National Standard, an ANSI Standard, or a United States of America Standards Institute (USASI) standard.