# NIOSH Pocket Guide to Chemical Hazards
Tributyl phosphate | CAS 126-73-8
(CH3[CH2]3O)3PO | RTECS TC7700000
Synonyms & Trade Names Butyl phosphate, TBP, Tributyl ester of phosphoric acid, Tri-n-butyl phosphate | DOT ID & Guide
Exposure Limits | NIOSH REL: TWA 0.2 ppm (2.5 mg/m3)
OSHA PEL†: TWA 5 mg/m3
IDLH 30 ppm | Conversion 1 ppm = 10.89 mg/m3
Physical Description Colorless to pale-yellow, odorless liquid.
MW: 266.3 | BP: 552°F (Decomposes) | FRZ: -112°F | Sol: 0.6%
VP(77°F): 0.004 mmHg | IP: ? |  | Sp.Gr: 0.98
Fl.P(oc): 295°F | UEL: ? | LEL: ? |
Class IIIB Combustible Liquid: Fl.P. at or above 200°F.
Incompatibilities & Reactivities Alkalis, oxidizers, water, moist air
Measurement Methods NIOSH 5034
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet or contaminated Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash promptly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH Up to 2 ppm: (APF = 10) Any supplied-air respirator Up to 5 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode Up to 10 ppm: (APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 30 ppm: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister having a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, respiratory system, headache; nausea
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION