Propane provides a safe, non-toxic source of energy. Nonetheless, it is crucial to quickly take action if you smell a gas leak in or near your home. Many people liken the odor of propane gas to “rotten eggs.” This scent comes from a substance all suppliers add to propane so that customers can detect leaks more easily. Some major leaks are accompanied by hissing sounds, but this does not always occur. If you suspect leakage, try to identify its source.