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Hydroquinone

Synonyms & Trade Names
1,4-Benzenediol, p-Benzenediol, Dihydroxybenzene, 1,4-Dihydroxybenzene, Quinol
CAS No.
123-31-9
RTECS No.
MX3500000
DOT ID & Guide
2662 153
Formula
C6H4(OH)2
Conversion
IDLH
50 mg/m3
See: 123319
Exposure Limits
NIOSH REL
C 2 mg/m3 [15-minute]
OSHA PEL
TWA 2 mg/m3
Measurement Methods
NIOSH 5004;
OSHA PV2094
See: NMAM or OSHA Methods
Physical Description
Light-tan, light-gray, or colorless crystals.
Molecular Weight
110.1
Boiling Point
545°F
Melting Point
338°F
Solubility
7%
Vapor Pressure
0.00001 mmHg
Ionization Potential
7.95 eV
Specific Gravity
1.33
Flash Point
329°F (Molten)
Upper Exposive Limit
?
Lower Explosive Limit
?
Combustible Solid; dust cloud may explode if ignited in an enclosed area.
Incompatibilities & Reactivities
Strong oxidizers, alkalis
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
irritation eyes: conjunctivitis; keratitis (inflammation of the cornea); central nervous system excitement; colored urine, nausea, dizziness, suffocation, rapid breath; muscle twitching, delirium; collapse; skin irritation, sensitization, dermatitis
Target Organs
Eyes, skin, respiratory system, central nervous system
Personal Protection/Sanitation
(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet or contaminated
Change:Daily
Provide:Eyewash (>7%)
First Aid
(See procedures)
Eye:Irrigate immediately
Skin:Water flush
Breathing:Respiratory support
Swallow:Medical attention immediately
Respirator Recommendations

NIOSH/OSHA

Up to 50 mg/m3:
(APF = 25) Any powered, air-purifying respirator with a high-efficiency particulate filter.£
(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters.
(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 with an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters.
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 0166   MEDICAL TESTS: 0120
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