Page:NIOSH Manual of Analytical Methods - 5522.pdf/5

 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

Ca = Carcinogen
 * 1 ppm = 7100 µg/m3 TDI; 10208 µg/m3 MDI; 7350 µg/m3 HDI;

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition