Ammonia

Colorless combustible toxic gas with a characteristic pungent smell. 
Lighter than air, density = 0,73 kg/m3 
Lower explosive limit (LEL) = 15 % vol 

Health exposure limits (Directive 2000/39/EC): 
- 8 hours TWA = 20 ppm (14 mg/m3) 
- 15 mins STEL = 50 ppm (36 mg/m3)

Ammonia