The investigation was launched after it was revealed that a glazed door used inside Grenfell Tower and produced by Manse Masterdor failed a 30-minute fire test. The door lasted for just 15 minutes in the test fire. Further tests showed that other doors made by a subsequent successor company also failed tests. A further three companies have since been found to be in breach of requirements.

The doors that failed the tests included both glazed and unglazed doors supplied by five firms including Permadoor, Solar Windows, Birtley Group and Masterdor. All companies are cooperating with the government in the investigations.

Communities Secretary James Brokenshire has said that the investigations are still ongoing, but there is now enough evidence to suggest that this could be a much broader issue across the entire market. He will be meeting with suppliers to ensure they understand the implications of these failures. He wants to see a clear plan of action to ensure failures do not continue. He does point out that risks are low, but that the government will do all it can to ensure that construction products are of the highest safety standards and are properly tested and marketed.

The manufacturers of fire doors are being asked to ensure their products meet the most recent fire regulations and that they have a clear plan of action to tackle any failings that have been identified. Experts have said that risk is low however as even those doors that failed are able to offer some fire resistance as part of the overall fire protection of any building.