Some experts believe that the use of building materials that comply with environmental protection standards in home decoration can only ensure that the content of harmful substances meets the requirements of relevant industries, and does not mean that they are completely free of harmful substances. Exceeding standards. From this we can infer:. ['The building materials industry should further tighten environmental standards.', 'The building materials industry should strive to reduce the content of harmful substances in products.', 'Choosing good building materials can effectively avoid unqualified indoor air quality.', 'Appropriate use of building materials can reduce harmful substances in indoor air.']