ANSI standards become mandatory OSHA standards only when, and if, they are adopted by OSHA; ANSI Z358.1 was not adopted by OSHA. In comparison with the OSHA standard at 29 CFR 1910.151(c), however, ANSI Z358.1 provides detailed information regarding the installation and operation of emergency eyewash and shower equipment. OSHA, therefore, has often referred employers to ANSI Z358.1 as a recognized source of guidance for protecting employees who are exposed to injurious corrosive materials.

OSHA would also take the ANSI standard into consideration when evaluating the adequacy of the protection provided by an employer. OSHA recognizes that there are differences between the 1990 and 1998 versions of ANSI Z358.1, and is planning to develop a compliance directive addressing this issue to ensure uniform and consistent enforcement of 29 CFR 1910.151(c). In the meantime, employers should assess the specific conditions in the workplace and determine whether compliance with the 1998 version of the ANSI Z358.1 will provide protection for employees that compliance with the 1990 version would not.

https://www.osha.gov/laws-regs/standardinterpretations/2002-03-28

Paragraph (c) of 29 CFR 1910.151 requires the employer to provide suitable facilities for quick drenching or flushing of the eyes and body when employees may be exposed to injurious corrosive materials. ANSI standards become mandatory OSHA standards only when, and if, they are adopted by OSHA; ANSI Z358.1 was not adopted by OSHA. In comparison with the OSHA standard at 29 CFR 1910.151(c), however, ANSI Z358.1 provides detailed information regarding the installation and operation of emergency eyewash and shower equipment. OSHA, therefore, has often referred employers to ANSI Z358.1 as a source of guidance for protecting employees who may be exposed to injurious corrosive materials.

As you may know, 29 CFR 1910.151(c) does not provide specific instruction regarding the installation and operation of emergency eyewash and shower equipment. Therefore, it is the employer’s responsibility to assess the particular conditions related to the eyewash/shower unit, such as water temperature, to ensure that the eyewash/shower unit provides suitable protection against caustic chemicals/materials to which employees may be exposed.

Since OSHA has a standard related to drenching/flushing facilities, any citation for the failure to provide suitable drenching/flushing facilities must be issued pursuant to 29 CFR 1910.151(c).

https://www.osha.gov/laws-regs/standardinterpretations/2002-04-18-1

If an eyewash or shower is considered to be unsuitable, a serious citation could be issued. The classification of the violation would have to be made on a case-by-case basis. If the Agency concluded that the failure to provide suitable eyewash or shower facilities presented a substantial probability that death or serious harm could result should an employee be exposed to a corrosive material in the workplace, and the Agency concluded that the employer “knew” of the unsuitable facilities, the agency would issue a “serious” violation under Section 17(k) of the OSH Act.

https://www.osha.gov/laws-regs/standardinterpretations/2002-11-01