What concentration of ammonia kills plants?

The concentration of ammonia that can harm or kill plants varies, but generally, levels above 100 mg/L can cause toxicity. At concentrations around 200-500 mg/L, many sensitive species may experience detrimental effects, including stunted growth and leaf damage. Higher concentrations, particularly above 1,000 mg/L, are likely to be lethal to most plants. Factors such as plant species, exposure duration, and environmental conditions also influence ammonia's impact.