Final answer:
The subject of 29 CFR 1926.1153 is the OSHA standard aimed at protecting construction workers from the hazard of respirable crystalline silica.
Step-by-step explanation:
29 CFR 1926.1153 is OSHA's standard covering the hazard related to respirable crystalline silica. This regulation is designed to protect workers in the construction industry from the dangers of silica dust, which can cause severe respiratory issues and other health problems. OSHA's regulation requires employers to limit workers' exposure to silica dust and take other safety measures, such as providing adequate respiratory protection and training employees on silica hazards and safety practices.