Canadian Entry To Practice (CETP) Practice Test 2026 - Free CETP Practice Questions and Study Guide

The correct answer is that ethyl mercaptan is the commonly used odorant for propane and it is added at a ratio of 1 pound per 10,000 gallons of propane. Ethyl mercaptan is favored because it imparts a distinctive and strong smell to the otherwise odorless propane, making it easier to detect leaks and prevent hazardous situations. The detection of this odor is crucial for safety, as propane can be dangerous if it accumulates without a noticeable odor.

The ratio of 1 pound per 10,000 gallons is a standard guideline that balances adequate odor detection with cost-effectiveness for propane suppliers. This amount ensures that even a small leak can be identified by the presence of the odor, thereby enhancing safety for users and surrounding areas.