September 2005

NIOSH Publication Number 2005-149 

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## Methylene bisphenyl isocyanate
Synonyms & Trade Names 4,4'-Diphenylmethane diisocyanate; MDI; Methylene b is(4-phenyl isocyanate); Methylene di-p-phenylene ester of isocyanic acid CAS No. 101-68-8 RTECS No. NQ9350000(/nioshrtecs/NQ8EAB70.html) DOT ID & Guide

Formula CH 2 (C 6 H 4 NCO) 2 Conversion 1 ppm = 10.24 mg/m IDLH 75 mg/m See: 101688 (/niosh/idlh/101688.html) Exposure Limits NIOSH REL : TWA 0.05 mg/m (0.005 ppm) C 0.2 mg/m (0.020 ppm) [10-minute] OSHA PEL : C 0.2 mg/m (0.02 ppm) Measurement Methods NIOSH 5521 (/niosh/docs/2003-154/pdfs/5521.pdf) , 5522 (/niosh/docs/2003-154/pdfs/5522.pdf) , 5525 (/niosh/docs/2003- 154/pdfs/5525.pdf) ; OSHA 18 (http://www.osha.gov/dts/sltc/methods/organic/org01 8/org018.html) See: NMAM (/niosh/docs/2003-154/) or OSHA Methods (http://www.osha.gov/dts/sltc/methods/index.html) Physical Description White to light-yellow, odorless flakes. [Note: A li quid above 99°F.]
MW: 250.3 BP: 597°

F MLT:

99°F Sol: 0.2% VP(77°F): 0.000005 mmHg IP: ?
Sp.Gr: 1.23 (Solid at 77°F) 1.19 (Liquid at 122°F) Fl.P: 390°

F UEL: ? LEL: ?

Combustible Solid Incompatibilities & Reactivities Strong alkalis, acids, alcohol [Note: Polymerizes a t 450°F.] Exposure Routes inhalation, ingestion, skin and/or eye contact Symptoms irritation eyes, nose, throat; resp sensitization; cough, pulmonary secretions, chest pain, dyspnea (breathing difficulty); asthma Target Organs Eyes, respiratory system Personal Protection/Sanitation (See protection codes (protect.html) ) First Aid (See procedures (firstaid.html) ) Eye: Irrigate immediately 3 3

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### Page 1 of 2 CDC

- NIOSH Pocket Guide to Chemical Hazards

- Methylene bisphenyl isocyanate

7/29/2010 http://www.cdc.gov/niosh/npg/npgd0413.htmlPage last reviewed: February 3, 2009

Page last updated: February 3, 2009 Content source: National Institute for Occupational Safety and Health (NIOSH) Education and Informatio n Division Centers for Disease Control and Prevention 1600 C lifton Rd. Atlanta, GA 30333, USA 800-CDC-INFO (800-232-4636) TTY: (888) 232-6348, 24 Hours/Every Day - cdcinfo@cdc.gov Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet or contaminated Change: Daily Skin: Soap wash immediately Breathing: Respiratory support Swallow: Medical attention immediately

Respirator Recommendations NIOSH Up to 0.5 mg/m : (APF = 10) Any supplied-air respirator* Up to 1.25 mg/m : (APF = 25) Any supplied-air respirator operated in a continuous-flow mode* Up to 2.5 mg/m : (APF = 50) Any self-contained breathing apparatus w ith a full facepiece (APF = 50) Any supplied-air respirator with a full facepiece Up to 75 mg/m : (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-deman d or other positive-pressure mode Emergency or planned entry into unknown concentrati ons or IDLH conditions: (APF = 10,000) Any self-contained breathing apparat us that has a full facepiece and is operated in a p ressuredemand or other positive-pressure mode (APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-dem and or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathi ng apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respir ator (gas mask) with a chin-style, front- or back-m ounted organic vapor canister having an N100, R100, or P10 0 filter. Click here (pgintrod.html#nrp) for information on selection of N, R, or P filters. Any appropriate escape-type, self-contained breathi ng apparatus Important additional information about respirator s election (pgintrod.html#mustread) See also: INTRODUCTION (/niosh/npg/pgintrod.html) See ICSC CARD: 0298 (/niosh/ipcsneng/neng0298.html) See MEDICAL TESTS: 0147 (/niosh/docs/2005-110/nmed0147.html) 3

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### Page 2 of 2 CDC

- NIOSH Pocket Guide to Chemical Hazards

- Methylene bisphenyl isocyanate

7/29/2010 http://www.cdc.gov/niosh/npg/npgd0413.html