PBD	Performance-Based Fire Safety Design	Lp	Light Path Length [m]
ASET	Available safe egress time	FDE	Fire detector evaluator
RSET	Required safe egress time	DB	database
FDS	Fire dynamics simulator	PE	Polyethylene
L	Characteristic length [m]	PP	Polypropylene
U	Free stream velocity [m/s]	PU	Polyurethane
$\mathsf{\delta }\mathrm{t}$	Dwell time	PVC	Polyvinyl chloride
$\mathsf{\tau }$	Mixing time	PS	Polystyrene
${\mathsf{\alpha }}_{\mathrm{e}}$, ${\mathsf{\beta }}_{\mathrm{e}}$, ${\mathsf{\alpha }}_{\mathrm{c}}$, ${\mathsf{\beta }}_c$	Additional input parameters	SSA	Single scattering albedo
OPM	Obscuration per meter [%/m]	Km	Mass specific extinction coefficient [m2/g]