# NIOSH Pocket Guide to Chemical Hazards
Dibutyl phosphate | CAS 107-66-4
(C4H9O)2(OH)PO | RTECS TB9605000
Synonyms & Trade Names Dibutyl acid o-phosphate, Di-n-butyl hydrogen phosphate, Dibutyl phosphoric acid | DOT ID & Guide
Exposure Limits | NIOSH REL: TWA 1 ppm (5 mg/m3) ST 2 ppm (10 mg/m3)
OSHA PEL†: TWA 1 ppm (5 mg/m3)
IDLH 30 ppm | Conversion 1 ppm = 8.60 mg/m3
Physical Description Pale-amber, odorless liquid.
MW: 210.2 | BP: 212°F (Decomposes) | FRZ: ? | Sol: Insoluble
VP: 1 mmHg (approx) | IP: ? |  | Sp.Gr: 1.06
Fl.P: ? | UEL: ? | LEL: ? |
Combustible Liquid
Incompatibilities & Reactivities Strong oxidizers
Measurement Methods NIOSH 5017
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet or contaminated Change: No recommendation Provide: Quick drench | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash promptly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 10 ppm: (APF = 10) Any supplied-air respirator Up to 25 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode Up to 30 ppm: (APF = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece 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
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION