Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

What distinct smell is associated with hydrogen sulfide?

1. Fresh bread

2. Chlorinated water

3. Rotten eggs and obnoxious

4. Pine forest

The correct answer is: Rotten eggs and obnoxious

Hydrogen sulfide is well-known for its distinct and unpleasant odor that closely resembles that of rotten eggs. This characteristic smell is due to the presence of sulfur in the chemical structure of hydrogen sulfide. The compound is often encountered in various environments, including natural sources like volcanic eruptions and the decomposition of organic matter, particularly in anaerobic conditions. Recognizing the odor of hydrogen sulfide is crucial, especially in water treatment and environmental monitoring, as its presence can indicate potential health and safety hazards. The ability to identify this foul smell allows operators and personnel to take necessary precautions to avoid exposure and mitigate risks associated with hydrogen sulfide. Other options do not accurately describe the smell of hydrogen sulfide. For instance, fresh bread and pine forest scents evoke pleasant and natural aromas, while chlorinated water has a more chemical scent associated with disinfectants, none of which are linked to the rotten egg smell.