LONDON (Reuters) - British laboratory tests on the fire safety of building materials are inadequate, research for the insurance industry in the wake of the Grenfell Tower fire showed on Wednesday.

FILE PHOTO: The burnt out remains of the Grenfell apartment tower is seen in North Kensington, London, Britain, September 24, 2017. REUTERS/Eddie Keogh

At least 71 people died in the fire in the social housing block in west London in June 2017.

Test fires for buildings only use wood, whereas plastic makes up 20 percent of the material in actual fires, according to the research commissioned by the Association of British Insurers.

Grenfell Tower was clad in plastic-filled aluminum panels.

A test fire containing 20 percent plastic was 100 degrees Celsius hotter than an all-wood fire, the research by the Fire Protection Association showed.

Also, cladding materials are sometimes tested as a sealed unit, but when they are fitted on a building they often include gaps, the research showed.

Materials are also tested in manufacturers’ conditions, but in use they are often pierced by vents or ducts, the research showed.

“The current cladding test standard requires urgent review to ensure that systems that pass are reflective ... of the risks to which they are exposed,” Jonathan O’Neill, managing director of the Fire Protection Association said.

Only non-combustible materials should be used in construction and the testing regime should be reformed to reflect real world conditions, the Association of British Insurers said in its submission to a government-commissioned independent review of buildings regulations and fire safety.

“Fundamental reform is needed to keep our homes and commercial premises safe from fire,” Huw Evans, director general of the ABI, said.

The ABI also called for mandatory sprinklers in new schools, care homes and warehouses of more than 2,000 square meters and a review of sprinklers in other buildings.

Installing sprinklers can cut property insurance premiums by up to 50 percent, the ABI said.

The final report from the independent review is expected in the next few weeks.