ISOCYANATES: METHOD 5521, Issue 2, dated 15 August 1994 - Page 5 of 6 REFERENCES: [1] [2]
[3] [4]
[5]
NIOSH - Measurement Research Support Branch Analytical Report, Sequences #6019, 6043, 6100, 6354, and 6878-C (NIOSH, unpublished, 1988). "MDHS 25: Methods for the Determination of Hazardous Substances, Organic Isocyanates in Air. Laboratory Method Using 1-(2-Methoxyphenyl)piperazine Solution and High Performance Liquid Chromatography," Occupational Medicine and Hygiene Laboratory, Health and Safety Executive, London, U.K. (1987). Bagon, D. A., C. J. Warwick, and R. H. Brown, Am. Ind. Hyg. Assoc. J., 45, 39-43(1984). NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, U.S. Department of Health and Human Services, Publ. (NIOSH) 81-123 (1981), available as GPO Stock #17-033-00337-8 from Superintendent of Documents, Washington, D.C. 20402 User check, DataChem Inc., NIOSH analytical seq. #6543 (unpublished, Feb. 24, 1989).
METHOD REVISED BY: M. J. Seymour and Rosa Key-Schwartz, Ph.D., NIOSH/DPSE
TABLE 1: SYNONYMS, EXPOSURE LIMITS, AND PROPERTIES Compounds (Synonyms)
Exposure Limits, µg/m3*
Properties
(OSHA)
(NIOSH)
(ACGIH)
2,4-TDI (toluene-2,4-diisocyanate)
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 -21.5 °C
2,6-TDI (toluene-2,-6-diiocyanate)
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
MDI 200 (4,4'-methylenediphenyl (ceiling) isocyanate; diphenylmethane4,4'-diisocyanate; methylenebis phenyl isocyanate)
50; 51 200/10 min (ceiling)
solid (fused); d 1.23 g/mL @ 25 °C; MP 37.2 °C; VP 0.0002 kPa (0.00014 mm Hg) @ 20 °C
HDI (hexamethylene diisocyanate)
no PEL
35 140/ 10/min (ceiling)
34
liquid; d 1.04 g/mL @ 20 °C; BP 255 °C; 0.007 kPa (0.05 mm Hg) @ 25 °C
NDI (naphthylene diisocyanate)
no PEL
40; 70/10 min
no TLV
solid flakes; MP 127 °C; VP <0.01 Pa @ 20 °C
- 1 ppm = 7100 µg/m3 TDI; 10208 µg/m3 MDI; 7350 µg/m3 HDI;
Ca = Carcinogen
APPENDIX A: PURIFICATION OF 1-(2-METHOXYPHENYL)PIPERAZINE AND PREPARATION OF NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
