what is permisible limits of nitrogen oxide and sulpher dioxide.?

Question

permisible level proposed by different countries for nitrogen oxide and sulpher dioxde.

Answer 1

NO
NIOSH REL: TWA 25 ppm (30 mg/m3)
OSHA PEL: TWA 25 ppm (30 mg/m3)

NO2
NIOSH REL: ST 1 ppm (1.8 mg/m3)
OSHA PEL†: C 5 ppm (9 mg/m3)

N2O
NIOSH REL*: TWA 25 ppm (46 mg/m3) (TWA over the time exposed)

O3
NIOSH REL: C 0.1 ppm (0.2 mg/m3)
OSHA PEL†: TWA 0.1 ppm (0.2 mg/m3)

SO2
NIOSH REL: TWA 2 ppm (5 mg/m3)
ST 5 ppm (13 mg/m3)
OSHA PEL†: TWA 5 ppm (13 mg/m3)