OSHA 30 Hour Construction Program Practice Test

According to regulations, how high must a guardrail be and how many rails should it have?

1. 36 inches and 2 rails

2. 42 inches and 3 rails

3. 48 inches and 4 rails

4. 40 inches and 3 rails

The correct answer is: 42 inches and 3 rails

The correct answer states that guardrails must be 42 inches high and should have 3 rails. This specification is critical for ensuring safety on construction sites, particularly in areas where there is a risk of falling. A guardrail system is an effective means of preventing falls from elevated surfaces, and the dimensions of 42 inches are specifically chosen to provide adequate protection for most workers. The height of 42 inches is necessary to avoid the risk of a worker slipping over the top of the guardrail, which could lead to serious injury or death. The requirement for three rails adds an additional layer of security. Typically, the top rail is at 42 inches, while the middle rail is positioned at about 21 inches, and another rail is placed at the bottom, usually around the walking surface. This design creates a barrier that not only helps prevent falls but also provides some impact resistance if a worker were to collide with the guardrail. These standards are established by OSHA to ensure that all construction sites prioritize worker safety, reducing the likelihood of falls and the severe consequences that can result from them.