Is a 1/2% concentration of Ammonia considered a deadly concentration?

A concentration of 1/2% ammonia, or 5000 parts per million (ppm), is not considered a lethal concentration. Instead, while ammonia is a highly irritating gas, a lethal concentration typically refers to much higher levels. A well-established threshold for immediate danger to health from ammonia exposure is significantly higher than this concentration.

Ammonia can cause irritation to the eyes, skin, and respiratory tract even at lower concentrations. Health guidelines such as those from OSHA (Occupational Safety and Health Administration) and ACGIH (American Conference of Governmental and Industrial Hygienists) provide exposure limits well above 1/2%.

Therefore, while it is essential to treat ammonia with caution and have appropriate safety measures in place due to its toxic properties, a concentration of 1/2% is generally not considered deadly, and this is why the correct answer is not true in this context.