Timber fire protection relates to nitrogen content
Scots pine boards (12 mm thickness) were tested for fire resistance without treatment after 2 hours impregnation (part vacuum) with solutions of a PIN fire retardant based on MAP, DAP and boric acid, plus urea or guanidine carbonate at 10%, 15% and 20%. Fire testing used the standard cone calorimeter (ISO 5660-1) and a modified ASTM E 69 Mini Fire test (MFT) method. Maximum heat release was reduced by a factor of 4-5 with all FR treatments, achieving EuroClass C. The fire resistance effectiveness increases with the number of nitrogen atoms present in the FR preparation.
“Effectiveness of new wood fire retardants using a cone calorimeter”, W. Grzeskowiak, J. Fire Sciences 2017, Vol. 35(6) 565–576 http://dx.doi.org/10.1177/0734904117737464