# NIOSH Pocket Guide to Chemical Hazards
Naphthalene | CAS 91-20-3
C10H8 | RTECS QJ0525000
Synonyms & Trade Names Naphthalin, Tar camphor, White tar | DOT ID & Guide 1334 133 (crude or refined) 2304 133 (molten)
Exposure Limits | NIOSH REL: TWA 10 ppm (50 mg/m3) ST 15 ppm (75 mg/m3)
OSHA PEL†: TWA 10 ppm (50 mg/m3)
IDLH 250 ppm | Conversion 1 ppm = 5.24 mg/m3
Physical Description Colorless to brown solid with an odor of mothballs. [Note: Shipped as a molten solid.]
MW: 128.2 | BP: 424°F | MLT: 176°F | Sol: 0.003%
VP: 0.08 mmHg | IP: 8.12 eV |  | Sp.Gr: 1.15
Fl.P: 174°F | UEL: 5.9% | LEL: 0.9% |
Combustible Solid, but will take some effort to ignite.
Incompatibilities & Reactivities Strong oxidizers, chromic anhydride
Measurement Methods NIOSH 1501; OSHA 35
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet or contaminated Change: Daily | First Aid (See procedures) Eye: Irrigate immediately Skin: Molten flush immediately/solid-liquid soap wash promptly Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 100 ppm: (APF = 10) Any chemical cartridge respirator with organic vapor cartridge(s) in combination with a dust and mist filter*/(APF = 10) Any supplied-air respirator* Up to 250 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode*/(APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s) in combination with a high-efficiency particulate filter/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s) in combination with a dust and mist filter*/(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, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes; headache, confusion, excitement, malaise (vague feeling of discomfort); nausea, vomiting, abdominal pain; irritation bladder; profuse sweating; jaundice; hematuria (blood in the urine), renal shutdown; dermatitis, optical neuritis, corneal damage
Target Organs Eyes, skin, blood, liver, kidneys, central nervous system
See also: INTRODUCTION