Figure 1.
Flame Retardancy Index (FRI) values as a function of phosphorus flame retardant (FR) type and content. Symbols are indicative of different types of phosphorus flame retardant used. Here: ■ APP-10 [24], 
APP-12, APP-15 [25], 
APP-20 [26],
APP-20 [27],
APP-20 [28],
APP-20 [23],
APP-25 [29],
APP-25 [30],
APP-25 [31],
APP-25 [32],
APP-25 [33],
APP-25 [34],
APP-25, m-APP-25 [35], 
APP-25, mc-APP-25 [36], 
m-APP-25 [37],
APP-30 [38],
APP-30 [39],
APP-30 [40],
mc-APP-30 [41],
APP-30, mc-APP-30 [42],
APP-30, mc-APP-30 [43],
APP-30, mc-APP-30 [44],
APP-30, mc-APP-5, mc-APP-10, mc-APP-15, mc-APP-20, mc-APP-25, mc-APP-30 [45], 
APP-35, m-APP-35 [46], 
APP-35, m-APP-35 [47], 
APP-40, mc-APP-40 [48], 
APP-25, P-CA-25 [49], 
APP-25 [50],
APP-IFR-20 [51],
P-IFR-10, P-IFR-15, P-IFR-20, P-IFR-25 [52],
P-IFR-20 [53],
P-IFR-28 [54],
P-IFR-28 [55],
PN-IFR-30 [56],
P-FR-30 [57],
P-FR-20 [58],
DOPO-10 [15],
mc-BDP-10, mc-BDP-20 [59],
OP-20 [60],
AHP-24 [61],
ALPi-30 [62],
PEPA-40 [63].