NO2 Data Sheet    NOx Data Sheet    

NO2 and NOx have implications for acidification of ecosystems and formation of ozone. It is pointed out that synergistic effects are very important and the guideline is given for NOx rather than NO2 alone.

WHO recommended a guideline to protect vegetation as an annual average of 30 µg/m3; for NOx, calculated as the sum of NO and NO2 in ppb and expressed as NO2 in mg/m3.

The annual limit value for the protection of vegetation is 30 µg/m3.

NO2 and NOx sampling

The passive samplers to measure NO2 and NOx consist of a polypropylene tube and are equipped with membranes. They are placed in specially designed shelters so as to protect them from weather conditions and make sure that they can accurately measure near spots with high traffic.