POLYMERIC 4,4’-METHYLENEDIPHENYL DIISOCYANATE (PAPI; polymeric MDI)

Chemical Identification
CAS #	9016-87-9
Formula	CH₂(C₆H₄NCO)₂
Synonyms	MDI oligomer; PMDI; polymeric MDI; polymeric isocyanate; polymeric 4,4’-methylenediphenyl diisocyanate; polymethylenepolyphenol isocyanate; polyphenyl isocyanate; PAPI

Physical Properties
Physical description	Dark-brown liquid with a weak odor.
Boiling point	392°F	Molecular weight	400 (approx)
Freezing point/melting point	200°C	Vapor pressure
Flash point	200°C	Vapor density
Specific gravity	1.2	Ionization potential
Lower explosive limit (LEL)		Upper explosive limit (UEL)
NFPA health rating		NFPA fire rating
NFPA reactivity rating		NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.)	P125
Sampling group
Sampler/Sampling media	Isocyanate Sampling Filter Kit - GFF (37 mm, open-faced) coated with 1 mg 1-(2-pyridyl)piperazine [SLTC103]
Sampling time^*	15 min
Sampling volume (TWA)^*
Sampling flow rate (TWA)^*
Sampling volume (STEL/Peak/C)^*	15 L
Sampling flow rate (STEL/Peak/C)^*	1 L/min
Analytical method instruments	UHPLC
Method reference	OSHA 5002 (fully validated)
Notes	Results may not reflect accurate exposures to the polymeric forms of isocyanates. Refrigerate coated filters. Sample open-faced!!
Special requirements

^* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Bulk/Wipe Method
Wipe Sampler/Sampling media
Bulk Method

On-Site Screening Techniques
Device
Model/Type
Sampling information (see manufacturer instructions)

**Exposure Limits**
OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak		NIOSH REL Up to 10-hour TWA (ST) STEL (C) Ceiling		ACGIH TLV© 8-hour TWA (ST) STEL (C) Ceiling		CAL/OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak
PEL-TWA		REL-TWA		TLV-TWA		PEL-TWA
PEL-STEL		REL-STEL		TLV-STEL		PEL-STEL
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	NA	Skin notation	NA	Skin notation	NA	Skin notation	NA
Notes: Not established		Notes: Not established		Notes: Not established		Notes: Not established
Health factors: See NIH-NLM PubChem.		IDLH
Carcinogenic classifications: EPA-D		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Polymeric diphenylmethane diisocyanate

NIOSH: Pocket Guide to Chemical Hazards - Polymeric diphenylmethane diisocyanate

Literature References

US EPA Integrated Risk Information System: Methylene Diphenyl Diisocyanate (monomeric MDI) and polymeric MDI (PMDI) (CASRN 101-68-8, 9016-87-9).
Baur, X.: Hypersensitivity pneumonitis (extrinsic allergic alveolitis) induced by isocyanates. J. Allergy Clin. Immunol. 95(5 Pt. 1): 1004-1010, 1995.
Bello, D., et al.: Polyisocyanates in occupational environments: a critical review of exposure limits and metrics. Am. J. Ind. Med. 46(5): 480-491, 2004.
Bonauto, D.K., Sumner, A.D., Curwick, C.C., Whittaker, S.G. and Lofgren, D.J.: Work-related asthma in the spray-on truck bed lining industry. J. Occup. Environ. Med. 47(5): 514-517, 2005.
Dalene, M., Skarping, G. and Lind, P.: Workers exposed to thermal degradation products of TDI- and MDI-based polyurethane: biomonitoring of 2,4-TDA, 2,6-TDA, and 4,4'-MDA in hydrolyzed urine and plasma. Am. Ind. Hyg. Assoc. 58(8): 587-591, 1997.
Feron, V.J., et al.: Chronic pulmonary effects of respirable methylene diphenyl diisocyanate (MDI) aerosol in rats: combination of findings from two bioassays. Arch. Toxicol. 75(3): 159-175, 2001.
Lamb, J.C., Huff, J.E., Haseman, J.K., Murthy, A.S. and Lilja, H.: Carcinogenesis studies of 4,4'methylenedianiline dihydrochloride given in drinking water to F344/N rats and B6C3F1 mice. J. Toxicol. Environ. Health 18(3): 325-337, 1986.
No authors listed: 4,4'-Methylenediphenyl diisocyanate and polymeric 4,4'-methylenediphenyl diisocyanate. IARC Monogr. Eval. Carcinog. Risks Hum. 71(Pt. 3): 1049-1058, 1999.

Last Updated Date : 04/19/2021

POLYMERIC 4,4’-METHYLENEDIPHENYL DIISOCYANATE (PAPI; polymeric MDI)

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References