Page:NIOSH Manual of Analytical Methods - 5525.pdf/12

 ISOCYANAT ES, TOTA L (MAP): METHO D 5525, Issue 1, dated 15 March 2003 - Page 12 of 17 TABLE 1. EXPOSURE LIMITS, PROPERTIES, CAS AND RTECS NUMBERS Isocyanates

Expo sure Limits µg /m 3*

Properties [11]

OSHA

NIOSH

AC GIH

(PEL)

(REL)

(TLV)

Toluene 2,6-diisocyanate (2,6-TDI)

no PEL

lowest feasible (Ca)

liquid; d 1.225 g/mL @ 25oC; MP no TLV 19.5-21.5/C; VP 3.33 Pa (0.025 mm Hg) @ 25oC [12]

Toluene 2,4-diisocyanate (2,4-TDI)

liquid; d 1.214 g/mL @ 25oC; MP 20lowest 22oC, VP 3.33 Pa (0.025 mm Hg) @ feasible 36 140 (Ca) 140 STEL 25oC [12] (ceiling)

4,4'-Methylenebis(phenyl isocyanate) (MDI)

50; 200 200 (10 min (ceiling) ceiling)

51

34

no PEL

35; 140 (10 min ceiling)

Isophorone diisocyanate (IPDI)

45

no PEL

45; 180 (10 min ceiling)

4,4'-Methylenebis(cyclohexyl isocyanate) (HMDI)

No REL; 110 (10 min no PEL ceiling)

1,6-Hexamethylene diisocyanate (HDI)

1,5-Naphthalene diisocyanate (NDI)



no PEL

40;70 (10 min ceiling)

54

CAS #

RTECS #

91-08-7

CZ6310000

584-84-9

CZ6300000

solid (fused); d 1.180g/mL @ 25oC; MP 42-44oC; VP 6x10-4 Pa (4.5x10-6 mm Hg) @ 25oC [12]

101-68-8 NQ9350000

liquid; d 1.04 g/mL @ 25oC; BP 255oC; 7 Pa (0.05 mm Hg) @ 25oC [13]

822-06-0 MO1740000

liquid; mixture of isomers, d 1.049 @ 25oC; MP -60oC [14]; VP 0.04 Pa @ 20oC (0.0003 mm Hg) [12] 4098-71-9 NQ9370000

liquid; mixture of isomers, d 1.066 g/mL @ 25oC; VP 0.13 Pa @ 20oC (0.001 mm Hg) [15]

5124-30-1 NQ9250000

solid flakes; MP 129-131oC [12]; VP 0.4 Pa @ 25oC (0.003 mm Hg) [12]

3173-72-6 NQ9600000

no TLV

1 ppb = 7.1 2 µg /m 3 TD I, 10.24 µg/m 3 MD I, 6.88 µ g/m 3 HD I, 9.09 µ g/m 3 IPD I, 10.73 µg/m 3 HM DI, 8.60 µg/m 3 NDI

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition