Flame Retardancy

Flame Retardant LOI (Limiting Oxygen Index) Predictor

LOI saturates. Doubling the add-on past the knee of the curve buys a point of LOI and a fabric nobody wants to wear.

FR System Response curve

Cotton ≈18.5, polyester ≈21, wool ≈25.

%

Add-on at which 63% of the achievable gain is reached.

Application Target
%

Predicted LOI

—

Limiting oxygen index at the applied add-on

Response

LOI Gained
—
Add-on for Target LOI
— %
Margin Over Threshold
—
Saturation of Achievable Gain
— %
LOI Gained per % Add-on
—

Decision-support only, and not a fire-performance claim. LOI is a laboratory ranking under forced oxygen, not a measure of behaviour in a real fire, and no product may be described as flame retardant on a calculated figure. The three curve constants must be fitted to your own fabric and chemistry, and certification requires testing to the governing standard.

Flame Retardant LOI (Limiting Oxygen Index) Predictor — free, with the formula and a worked example, at Textile School.