The purpose of the Regulations is to establish limit values for concentrations of benzene and carbon monoxide in ambient air of the Republic with a view to avoiding, preventing or reducing harmful effects on human health and the environment throughout the Republic, the assessment of concentrations of these pollutants in ambient air using common methods and criteria to obtain adequate information on such concentrations and the information of the public as well as maintaining or improving air quality regarding those pollutants. In particular, the Regulations set limits on concentrations of benzene and carbon monoxide in ambient air and upper and lower assessment thresholds. In addition, the Regulations set criteria for determining the locations of sampling points for the measurement of these pollutants. They also specify specific methods of reference or equivalent methods by which the concentrations of benzene and carbon monoxide should be measured. The adoption of the present Regulations is made under article 8 of the Air Quality Act of 2002.