# NIOSH Pocket Guide to Chemical Hazards
Borates, tetra, sodium salts (Decahydrate) | CAS 1303-96-4
Na2B4O7 • 10H2O | RTECS VZ2275000
Synonyms & Trade Names Borax, Borax decahydrate, Sodium borate decahydrate, Sodium tetraborate decahydrate | DOT ID & Guide
Exposure Limits | NIOSH REL: TWA 5 mg/m3
OSHA PEL†: none
IDLH N.D. | Conversion
Physical Description White, odorless, crystalline solid. [herbicide] [Note: Becomes anhydrous at 608°F.]
MW: 381.4 | BP: 608°F | MLT: 167°F | Sol: 6%
VP: 0 mmHg (approx) | IP: NA |  | Sp.Gr: 1.73
Fl.P: NA | UEL: NA | LEL: NA |
Noncombustible Solid (an inherent fire retardant).
Incompatibilities & Reactivities Zirconium, strong acids, metallic salts
Measurement Methods NIOSH 0500; OSHA ID125G
Personal Protection & Sanitation Skin: No recommendation Eyes: No recommendation Wash skin: Daily Remove: No recommendation Change: Daily | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations To be added later
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, upper respiratory system; dermatitis; epistaxis (nosebleed); cough, dyspnea (breathing difficulty)
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION