BS 6853 Annex D smoke density
BS 6853 Annex D: Methods for measuring smoke density. BS6853-code of practice of fire precautions in the design and construction of passenger carrying trains (fire-test.com).
The BS6853 smoke density measurement taken from a material under fire conditions gives an indication of the visibility through the smoke, this is important as reduced visibility in a real fire situation makes it more difficult to escape from a fire hence increasing the threat to human life from the toxic gases, flames and heat.
There are five different test methods which can be utilized to determine the smoke density produced from materials to be placed on passenger carrying trains in the UK.
The five different methods are as follows:
BS 6853 Annex D.8.3 – small scale test method
BS 6853 Annex D.8.4 – panel test method
BS 6853 Annex D.8.5 – seat test method
BS 6853 Annex D.8.6 – floor test method
BS 6853 Annex D.8.7 – cable test method
BS 6853 Annex D.8.3 is utilized for minor use materials (Tables 7 and 8 of BS 6853: 1999) and textiles (Table 11 of BS 6853: 1999).
BS 6853 Annex D.8.4 is utilized for interior and exterior vertical surfaces and horizontal prone surfaces (Tables 2, 3, 5 and 6 of BS 6853: 1999) and seat shell (table 10 of BS6853: 1999).
BS 6853 Annex D.8.5 is utilized for seats (Tables 9 of BS6853: 1999).
BS 6853 Annex D.8.6 is utilized for interior and exterior horizontal supine surfaces (Tables 1 and 4 of BS 6853:1999) and mattresses (table 12 of BS 6853: 1999).