Cooking and food enterprises that emit oil fume must install oil fume purification facilities and ensure that they operate as required during operation. The unorganized emission of lampblack is regarded as exceeding the standard. The length of the outlet section of the exhaust pipe should be at least 4.5 times the diameter (or equivalent diameter) of the straight pipe section. The outlet of the exhaust pipe should be oriented away from vulnerable buildings. The specific provisions on the height and position of the fume exhaust pipe shall be formulated by the provincial environmental protection department.

article 49 of the law of the people's Republic of China on the prevention and control of air pollution

combustible gases produced by industrial production, landfill or other activities should be recycled, and pollution prevention and treatment should be carried out if the conditions for recycling are not met. If the combustible gas recovery and utilization device cannot operate normally, it shall be repaired or updated in time. If it is really necessary to discharge combustible gas during the period when the recycling device cannot operate normally, it shall fully burn the discharged combustible gas or take other measures to control the emission of atmospheric pollutants, and report to the local competent department of ecological environment, and repair or update it within a time limit as required.