Legal analysis: If food containing foreign substances does not meet food safety standards, such as hair in food, consumers have the right to request catering service providers according to Article 148 of the Food Safety Law.

Legal basis: People's Republic of China (PRC) Food Safety Law.

Article 106 In the event of a food safety accident, the food safety supervision and administration department of the people's government at or above the municipal level divided into districts shall immediately investigate the accident liability in conjunction with the relevant departments, urge the relevant departments to perform their duties, and submit a report on the investigation and handling of the accident liability to the people's government at the same level and the food safety supervision and administration department of the people's government at the next higher level.

Major food safety accidents involving more than two provinces, autonomous regions and municipalities directly under the Central Government shall be investigated by the food safety supervision and administration department of the State Council in accordance with the provisions of the preceding paragraph.

Article 107 In investigating food safety accidents, we should adhere to the principles of seeking truth from facts and respecting science, promptly and accurately identify the nature and causes of accidents, identify the responsibility for accidents, and put forward rectification measures.

When investigating food safety accidents, it is necessary to find out not only the responsibility of the accident unit, but also the responsibility of the relevant supervision and management departments, food inspection agencies, certification bodies and their staff.