ISOCYANATES: METHOD 5522, Issue 2, dated 15 January 1998 - Page 5 of 6 TABLE 1: SYNONYMS, EXPOSURE LIMITS, AND PROPERTIES MW
Exposure Limits, µg/m3*
(g/mol)
(OSHA)
(NIOSH) (ACGIH)
2,4-TDI (toluene-2,4diisocyanate)
174.16
140 (ceiling)
lowest feasible (Ca)
36; 140 STEL (Ca)
liquid; d 1.224 g/mL @ 20 C; BP 251 C; VP 1.3 Pa (0.01 mm Hg) @ 20 C; MP 19.5 to 21.5 C
2,6-TDI (toluene-2,-6diiocyanate)
174.16
no PEL
lowest feasible (Ca)
no TLV
liquid; d 1.22 g/mL @ 20 C; VP 1.3 Pa (0.01 mm Hg) @ 20 C
250.26 MDI (4,4'-methylenediphenyl isocyanate; diphenylmethane-4,4'diisocyanate; methylenebis phenyl isocyanate)
200 (ceiling)
50; 200/10 min (ceiling)
51
solid (fused); d 1.23 g/mL @ 25 C; MP 37.2 C; VP 0.19 Pa (0.00014 mm Hg) @ 25 C
168.20
no PEL
35; 140/10 min (ceiling)
34
liquid; d 1.04 g/mL @ 20 C; BP 255 C; 7 Pa (0.05 mm Hg) @ 25 C
Compounds (Synonyms)
HDI (hexamethylene diisocyanate)
Properties
- 1 ppm = 7100 µg/m3 TDI; 10208 µg/m3 MDI; 7350 µg/m3 HDI;
Ca = Carcinogen
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition
