An excerpt from OSHA’s Standard Interpretations page.

As described in OSHA’s Portland Cement Inspection Procedures, work with portland cement is covered by OSHA’s three sanitation standards. Which standard applies depends on whether the work is in general industry, construction, or shipyards. OSHA’s standard for washing facilities at construction sites, 29 CFR 1926.51(f)(1), states,

The employer shall provide adequate washing facilities for employees engaged in the application of paints, coating, herbicides, or insecticides, or in other operations where contaminants may be harmful to employees. Such facilities shall be in near proximity to the worksite and shall be so equipped to enable employees to remove such substances.

OSHA’s standard for washing facilities in shipyards, 29 CFR 1915.97(b), states,

The employer shall provide adequate washing facilities for employees engaged in the application of paints or coatings or in other operations where contaminants can, by ingestion or absorption, be detrimental to the health of the employees. The employer shall encourage good personal hygiene practices by informing the employees of the need for removing surface contaminants by thorough washing [of] hands and face prior to eating or smoking.

Finally, OSHA’s standard for washing facilities in general industry, 29 CFR 1910.141(d)(2), Lavatories, states,

(i) Lavatories shall be made available in all places of employment….
(ii) Each lavatory shall be provided with hot and cold running water, or tepid running water.
(iii) Hand soap or similar cleansing agents shall be provided.
(iv) Individual hand towels or sections thereof, of cloth or paper, warm air blowers or clean individual sections of continuous cloth toweling, convenient to the lavatories, shall be provided.

As explained in OSHA’s Portland Cement Inspection Procedures, we interpret all three of these standards to require employers to provide clean water, non-alkaline soap, and clean towels at worksites where employees are working with portland cement. We read your inquiry to be asking whether a pH buffer solution may substitute for non-alkaline soap, or a combination of clean water and non-alkaline soap, for the removal of wet portland cement from the skin. OSHA recognizes that the use of pH buffering solutions may aid in preventing skin problems where there is exposure to wet cement. Therefore, our response to your question is a qualified “yes.” Providing pH buffer solution could meet the requirements of OSHA’s sanitation standards as long as the use of the pH buffer solution would enable employees to remove the substance(s) that pose(s) the dermal hazard(s).