Downlighters - can they be a fire hazard?

The Electrical Safety Council ( ESC ) have been working with the Surrey Fire and Rescue Service to investigate concerns that incorrectly selected, installed and/or maintained downlighters may have been the cause of a significant number of fires in homes.
As part of the investigation, they commissioned an independent laboratory to carry out a limited safety assessment of, and thermal performance testing on, a selection of commercially-available downlighters.
Eight downlighters were selected to include a broad range of lamp type, fitting design and price, and assessed against the requirements for safety and performance specified in product standards applicable to ‘recessed luminaires’.
In essence, the downlighters were first tested when installed in accordance with the manufacturers’ instructions, and then when covered over with two layers of 100 mm thick thermal insulation.
For all but one of the downlighters, covering the luminaire was considered to be an ‘abnormal’ mode of operation which contravened the installation instructions. However, being covered in thermal insulation or other material is reportedly one of the main reasons for downlighters being the source of fires.

A detailed report giving a full description of the samples, the tests applied and findings of the assessment can be found here