Final answer:
Excavation safety standards were introduced by OSHA in 1. 1989. These standards are designed to protect workers from several hazards, including trenching cave-ins, and are a critical component of workplace safety in the construction industry.
Step-by-step explanation:
Excavation safety standards have been a critical part of worker protection in the construction industry. These standards are essential for preventing workplace injuries, such as those from trenching cave-ins. Worker safety regulations, as promulgated by the Occupational Safety and Health Administration (OSHA), have evolved over time to address a range of serious hazards in the workplace.
The correct answer to the question 'When were excavation safety standards introduced?' is 1. 1989. This was the year when OSHA introduced specific safety standards aimed at protecting workers involved in excavation activities. The standards were part of OSHA's Construction, General Industry, Maritime, and Agriculture standards, designed to provide a broad spectrum of protections for workers from various industry-related hazards.
These standards include requirements for fall protection, trenching safety, and protective equipment use. It's important for employers to comply with OSHA standards to ensure the safety and health of their employees.