Which statement about tool safety is true?

The statement indicating that tools with loose handles may slip on the fastener is accurate because a secure grip is essential for safe operation. A loose handle can compromise the user's ability to control the tool effectively, leading to potential accidents or injuries. If the handle slips while applying force, it could not only result in a loss of precision when working but could also cause the tool to slip loose, presenting a hazard to the user and those nearby.

In contrast, the other statements lack validity regarding tool safety. Routine inspections are crucial in ensuring tools are functioning properly and safely. Tools can pose safety risks depending on their condition; hence, not all tools are inherently safe. Additionally, simply adding more grease does not inherently improve tool safety and could potentially lead to other issues, such as attracting dirt or interfering with the proper functioning of the tool.