Risk Management for Hazardous Chemicals Page: 1

©1996 by CRC Press, Inc.

MATERIAL SAFETY DATA SHEETCHEMICAL NAME

HYDROQUINONE

CRC PRESS/LEWIS PUBLISHERS DISCLAIMER: THE INFORMATION AND RECOMMENDATIONS

PRESENTED HEREIN ARE BASED ON SOURCES BELIEVED TO BE RELIABLE. CRC MAKES NO REPRESENTATION ONITS COMPLETENESS OR ACCURACY. IT IS THE RESPONSIBILITY OF THE USER TO DETERMINE THE CHEMICAL'SSUITABILITY FOR ITS INTENDED USE, THE CHEMICAL'S SAFE USE, AND THE CHEMICAL'S PROPER DISPOSAL. NOREPRESENTATIONS AND/OR WARRANTIES, EITHER EXPRESSED OR IMPLIED, OF THE MERCHANTABILITY ORFITNESS FOR A PARTICULAR PURPOSE, OR OF ANY OTHER NATURE, ARE MADE WITH RESPECT TO THE IN-FORMATION PROVIDED IN THIS MSDS OR TO THE CHEMICAL TO WHICH INFORMATION MAY REFER. CRCNEITHER ASSUMES NOR AUTHORIZES ANY OTHER PERSON TO ASSUME FOR IT, ANY OTHER ADDITIONAL RE-SPONSIBILITY OR LIABILITY FOR THE USE OF, OR RELIANCE UPON, THIS INFORMATION.

HAZARD WARNING INFORMATIONHEALTH FIRE REACTIVE OTHER DEGREE OF HAZARD COLOR CODING OTHER CODES

2 1 00 = Minimum Hazard1 = Slight Hazard2 = Moderate Hazard3 = Serious Hazard4 = Severe Hazard

HEALTH = BLUEFIRE = REDREACTIVITY = YELLOWOTHER = WHITE

OX = OxidizerACID = AcidALK = AlkaliCOR = CorrosiveW = Use No Water

SECTION I - GENERAL INFORMATIONCharacterization

HydrocarbonRCRA Number

NoneEPA Class

Not ApplicableDOT Proper Shipping Name

Hydroquinone, liquid and solidChemical Abstract Service (CAS) Number

123-31-9DOT Hazard Class and Label Requirements

IMO Poison B; St. Andrews CrossDOT Emergency Guide Code

53DOT Identification Number

UN 2662Chemical Formula

C6H4(OH)2Synonyms

p-Benzenediol; 1,4-benzenediol; dihydroxybenzene; Quinol; hydroquinol; pyrogentisic acid.

SECTION II - HAZARDOUS INGREDIENTS AND IDENTITY INFORMATIONHazardous Components (specific identity) OSHA Exposure Criteria NIOSH Exposure Criteria Immediately Dangerous to

Life and Health (IDLH)ACGIH Exposure Criteria

Hydroquinone (derivation: By oxida-tion of aniline to quinone with manganesedioxide followed by reduction to hydroqui-none with sulfurous acid).

PEL (8-hour): 2 mg/m 3

STEL: Not Established

REL (ceiling): 2 mg/m 3

(15 minute)

STEL: Not Applicable

50 mg/m 3

TLV: 2 mg/m 3

STEL: Not Established

SECTION III - PHYSICAL AND CHEMICAL CHARACTERISTICSBoiling Point

546°°F (286°°C)Specific Gravity (H2O = 1)

1.33Vapor Pressure (gas)

1 x 10-5 at 69°°F (20°°C)Molecular Weight

98.2Vapor Density (Air = 1)

3.81Melting Point

338°°F (170°°C)Solubility

Soluble in water (7%), alcohol, acetone, carbon tetrachloride, and ether. Slightly soluble in benzene.Appearance and Odor

Colorless, light gray, or light tan hexagonal crystals. Color change depends on degree of oxidation.

SECTION IV - FIRE AND EXPLOSION HAZARD DATAFlash Point (method used)

329°°F (165°°C) closed cupExplosive Limits in Air % by Volume

LEL: Not Determined UEL: Not DeterminedNFPA Classification

Combustible SolidAutoignition Temperature

960°°F (515°°C)Extinguishing Media

Use dry chemical, carbon dioxide, water spray, or regular foam.Special Fire Fighting Procedures

Wear full protective clothing and self-contained breathing apparatus (SCBA). Poisonous gases are pro-duced in fire. Use water spray to keep fire-exposed containers cool. Containers may explode in fire.Unusual Fire and Explosion Hazards

Combustible solid. Its dusts can form a cloud that may explode if ignited in a closed area. Move contain-ers from fire area if it can be done without risk. Violent reactions can occur with oxidizers. Do not releaserunoff from fire methods to sewers or waterways.

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©1996 by CRC Press, Inc.

SECTION V - REACTIVITY DATA

StabilityConditions to Avoid

Hydroquinone turns brown on exposure to light and air due to oxidation, which becomes more rapid inthe presence of alkali. Avoid contact with incompatible materials. Do not generate dusty conditions.

Stable Unstable

X

Incompatibility (materials to avoid)

Strong oxidizers (permanganates, peroxides, nitrates, chlorates, and perchlorates), and alkalis. Reactsviolently with sodium hydroxide, forms p-benzoquinone with chlorine, and is explosive with heated oxy-gen.

HazardousPolymerization

Conditions to Avoid

Under normal conditions of temperature and pressure, hazardous polymerization of hydroquinone is notexpected to occur.

May Occur Will Not Occur

X

Hazardous Decomposition or By-products

When heated to decomposition, hydroquinone can emit highly toxic/poisonous and acrid fumes andgases including toxic quinone and carbon dioxide fumes.

SECTION VI - HEALTH HAZARD DATA

Primary Route(s) of Entry:Inhalation?

X

Absorption (skin)? Ingestion?

XHealth Hazards

INHALATION: Symptoms include irritation of the nose, throat, and respiratory tract. There may also be central nervous system depression causing excitement, dizziness, and collapse.

SKIN & EYES: Irritating to the skin; may cause irritation and dermatitis. An eye irritant with possibility of corneal damage, conjunctivitis, and keratitis. May cause brownish staining of eye tissue.

INGESTION: Serious human poison causing ringing in the ears, nausea, dizziness, vomiting, pallor, a feeling of suffocation, increased respiration, muscular twitching, headache, dypsnea, cyanosis, delirium, collapse, urine color change (green or brownish green), convulsions, blurred speech, tremors, and severe gastrointestinal disturbances.Carcinogenicity

Unknown HumanQuestioned Animal

NTP Listed?

No

IARC Cancer Review Group?

Group 3

OSHA Regulated?

29 CFR 1910.1000Table Z-1

Target Organs?

Respiratory system, eyes,skin, CNS, bladder.

Medical Conditions Generally Aggravated by Exposure

Skin diseases may be aggravated by exposure.Emergency and First-aid Procedures

Eye contact: Flush immediately with water for 15 minutes (minimum); seek medical attention. Skin co n-tact: Remove all contaminated clothing. Immediately wash area with large amounts of soap and water.Seek medical assistance. For inhalation: Remove the person from exposure. Provide respiratory assis-tance and CPR, if required. Transfer to medical facility. Keep victim warm and at rest. If swallowed: Seekmedical attention immediately. Give conscious person 1 to 2 glasses of water to dilute. Do NOT inducevomiting. DOCTOR: Consider gastric lavage and a urine screen test.

SECTION VII - PRECAUTIONS FOR SAFE HANDLING AND USESteps to be Taken in Case Material is Released or Spilled

Collect powders using HEPA vacuum. Do NOT dry sweep. Absorb solution spills in vermiculite and placein sealed drum. Ventilate area of spill or leak. Remove all sources of ignition.Preferred Waste Disposal Method

No Citation.Precautions to be Taken in Handling and Storage

Store to avoid contact with incompatible materials in tightly closed containers in cool, dry, well-ventilatedarea away from heat, flame, and direct sunlight. Use only non-sparking tools.Other Precautions and Warnings

Sources of ignition are prohibited where hydroquinone is used, handled, or stored.

SECTION VIII - CONTROL MEASURES AND PERSONAL PROTECTIVE EQUIPMENTRespiratory Protection (specify type)

For exposures above the PEL, use a MSHA/NIOSH-approved supplied-air respirator with full facepiece,hood, or helmet in continuous flow mode, or use a self-contained breathing apparatus (SCBA) operated inpressure demand or other positive pressure mode.Ventilation

Local exhaust or general mechanical systems recommended.Protective Gloves

PVC, Chlorinated PolyethyleneEye Protection

Chemical/Dust Goggles or Face MaskOther Protective Clothing

Protective ApronWork/Hygiene Practices

Always wash hands thoroughly after using chemical; never bring food, drink, or smoking materials intovicinity of chemicals.

Risk Management for Hazardous Chemicals Page: 3

©1996 by CRC Press, Inc.

HYDROQUINONEC6H4(OH)2 CAS: 123-31-9

OH

OH

21

0

IDENTIFICATION AND TYPICAL USES

Hydroquinone is a colorless, light-tan, or light-gray,crystalline (hexagonal) solid in the shape of prisms.The degree of color change is dependent upon thelevel of oxidation. It is used as a reducing agent, inblack and white photography development, as a dyeintermediate, as an inhibitor, as a stabilizer in paintsand varnishes, in motor fuels and oils, as an antioxi-dant for fats and oils, as an inhibitor of polymeriza-tion, and in skin hyper-pigmentation.

RISK ASSESSMENT: HEALTHGeneral Assessment

Hydroquinone is moderately toxic by ingestion andinhalation. It will cause moderate health hazard riskon skin or eye contact, but absorption through intactskin has not been reported. Its carcinogenicity in hu-mans is not known but is questioned in some animalstudies. It has been shown to cause mutations (geneticchanges) in human cells. Experimental reproductivedata have also been reported in animal tests. Hydro-quinone is metabolized in the body to more toxic qui-none which is responsible for the compound’s sys-temic toxicity.

Inhalation of the dusts causes irritation of thenose, throat, and mucous membranes of the respiratorytract. It may also cause central nervous system distur-bances similar to those caused by ingestion.

Skin and eye contact may produce mild to moder-ate irritation on contact. It can cause sensitizationand eczematous dermatitis. Direct eye contact withhydroquinone particles causes immediate irritationand possible corneal ulceration.

Ingestion of hydroquinone causes serious toxicsystemic effects. It is readily absorbed through thedigestive process. There will be initial gastrointestinal

irritation followed by central nervous system effectsincluding blurred speech, ringing in the ears, tremors,a feeling of suffocation, headache, muscular twitching,vomiting, nausea, convulsions, dypsnea, cyanosis andmethemoglobinemia, coma and unconsciousness, col-lapse, and possibly death due to respiratory failure.There may be changes in the color of the urine togreen or brownish-green.

1 Acute Health Effects

The following acute (short-term) health effects mayoccur immediately or shortly after exposure to hydro-quinone:

Skin: Will defat the skin and cause irritation anddermatitis (eczematous) and sensitization.

Eye: Severe irritation with a potential for cornealinjury or damage.

Lung: Nose and throat irritation. Produces centralnervous system effects and may cause lung ef-fects as well.

CNS: Numerous effects by ingestion and inhalation.There may be headaches, muscle twitching,convulsions, dypsnea, blurred speech, ringingin the ears, tremors, coma, collapse, and death.

0 Chronic Health Effects

The following chronic (long-term) health effects mayoccur at some time after exposure to hydroquinoneand can last for months or even years:

Cancer Hazards: According to information presentedin the references, hydroquinone has been shown tocause cancer in some test animals. However, the dataare conflicting and inconclusive in this regard. Somestudies indicate that it causes mutations in humans.

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©1996 by CRC Press, Inc.

Some studies have listed its cancer causing propertiesas questioned animal studies.

Reproductive Hazard: According to information pre-sented in the references, hydroquinone may have theability to adversely affect reproduction in animals.The teratogenicity of hydroquinone in humans has notbeen adequately studied.

Other Chronic Effects: Prolonged contact may causebrownish staining of the conjunctiva followed by cor-neal changes and possible loss of visual acuity. Re-peated skin contact can lead to chronic dermatitis andmay cause de-pigmentation (in darker-skinned people)and hyper-pigmentation (in fair-skinned persons).

Ä Recommended Risk-Reduction Measures

Personnel should avoid direct contact with hydroqui-none. The exact nature of the toxicity of this chemicalis not entirely understood in the references. There-fore, prudent risk management requires it be treated asthough it posed a significant health risk in the event ofoverexposure. If a less toxic chemical cannot be sub-stituted for a hazardous substance, then engineeringcontrols are the most effective method of reducingexposures. The best protection is to enclose opera-tions and/or provide local exhaust ventilation at thesite of chemical release. While not always operation-ally feasible, isolating operations can also reduce ex-posure. Using respiratory protection is less effectivethan the controls mentioned above, but is still advis-able whenever working with or around hydroquinone.The exposure ceiling is relatively low (2 mg/m3) anddifficult to accurately monitor. For all exposures, asupplied-air respirator with full facepiece operated incontinuous flow mode, or a self-contained breathingapparatus (SCBA) with full facepiece and pressuredemand are the recommended respiratory protectionmethods of choice. If a full facepiece is not available,then chemical goggles should be worn to protect theeyes. Whenever a chemical splash hazard exists, aface shield and a rubber apron should be worn. Toprevent hand and skin exposures, impervious polyvi-nyl chloride or polyethylene gloves should be used.Glove manufacturers should be contacted to obtainpermeation studies before glove selection has beenmade for hydroquinone.

Administrative controls should also be in place tominimize the potential for human exposures. Thesemay include written procedures or policies whichspecify the methods and techniques that will be prac-ticed whenever personnel are to work with hydroqui-none.

All personnel should receive training on the use,hazards, protective measures, emergency actions, andother precautions per 29 CFR 1910.1200 (HazardCommunication), prior to the first assignment in anarea where hydroquinone is used or stored.

If symptoms develop or overexposure is suspected, thefollowing tests are recommended:

; Kidney function tests and urinalysis (check forcolor changes).

; Evaluation by a qualified allergist, with carefulconsideration of exposure history and special skintests (may help diagnose allergy).

; Evaluation for nervous system disorders.

Any evaluation should include a careful history of pastand present symptoms with an examination. Medicaltests that simply look for existing damage are not asubstitute for controlling exposures.

Other methods to reduce exposure include:

; Where possible, enclose operations and use localexhaust ventilation at the site of chemical release.If local exhaust ventilation or enclosure is notused, respiratory protection should be mandatory.Also, if possible, automatic transfer of hydroqui-none from storage containers to process or workcontainers is recommended.

; Always ensure that proper protective clothing isworn when using chemical substances and thatpersonnel are trained in its proper use and care.

; Wash thoroughly immediately after exposure tohydroquinone and at the end of the work shift orbefore eating, drinking, or smoking.

; Hazard warning information should be posted inthe work area. In addition, as part of an on-goingeducation and training program, all informationon the health and safety hazards of hydroquinoneshould be communicated to all exposed and po-tentially exposed workers.

; Eye wash stations should be provided in the im-mediate work area for emergency use. If there isa possibility of skin exposure to hydroquinone,emergency shower facilities should also be pro-vided in the immediate work area.

; Personnel should never wear contaminatedclothing home (family members can be exposed).Clothing should be laundered by personnel whohave been trained on the hazards of hydroqui-none.

RISK ASSESSMENT: ENVIRONMENT

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©1996 by CRC Press, Inc.

General Assessment

The environment is at risk of exposure during trans-portation, storage, disposal, or destruction of hydro-quinone. In almost every scenario, the threat of envi-ronmental exposure is contingent upon the properhandling of the chemical substance. Accidental spills,large or small, can result in fire, explosion, and possi-ble contamination of the surrounding environmentalmediums (water, soil, and air).

Hydroquinone is considered a combustible solid.A cloud of hydroquinone dusts may explode if ignitedin an enclosed area. It also presents a moderate fireand explosion hazard risk, especially in contact withincompatible materials. These characteristics requireextreme caution in handling, storage, transportation,and disposal. It is incompatible with strong oxidizersand alkalis and contact can cause fire or explosion. Itreacts violently with sodium hydroxide and forms p-benzoquinone with chlorine. Therefore, special con-sideration is required during any emergency situationinvolving a leak or spill of hydroquinone. Should hy-droquinone ever come into contact with these incom-patible substances during use, transportation, storage,or disposal, the formation of highly toxic and/orhighly explosive commodities is extremely possible.

Hydroquinone may enter the environment throughindustrial discharges or spills.

1 Acute Ecological Effects

Acute (short-term) toxic effects may include the deathof animals, birds, or fish and death or low growth ratein plants. Acute effects are seen 2 to 4 days after ani-mals or plants are exposed to hydroquinone.

Hydroquinone has high acute toxicity to aquaticlife and has caused germination decrease in agricul-tural crops. Insufficient data are available on theshort-term effects of hydroquinone exposure to birdsor terrestrial animals.

0 Chronic Ecological Effects

Chronic (long-term) toxic effects may include short-ened life span, reproductive problems, lower fertility,and changes in appearance or behavior in exposedanimals. These effects can be seen long after first ex-posure(s) to toxic chemicals.

Hydroquinone has high chronic toxicity to aquaticlife. Insufficient data are available on the long-termeffects of hydroquinone exposure to birds, plants, orterrestrial animals.

6 Water Solubility

Hydroquinone is highly soluble in water. Concentra-tions of 1000 milligrams and more will mix with aliter of water.

� Persistence in the Environment

Hydroquinone is slightly persistent in water, with ahalf-life between 2 to 20 days. The half-life of a pol-lutant is the amount of time it takes for one half of thechemical to be degraded. About 99% of hydroquinonewill eventually end up in water; the rest will end up inair.

O Bioaccumulation in Aquatic Organisms

Some substances increase in concentration, or bioac-cumulate, in living organisms as they breathe con-taminated air, drink contaminated water, or eat con-taminated food. These chemicals can become con-centrated in the tissues and internal organs of animalsas well as humans.

The concentration of hydroquinone found in fishtissue is expected to be about the same as the averageconcentration of hydroquinone in the water fromwhich the fish was taken.

ÄÄ Recommended Risk-Reduction Measures

Proper training of all transporters will reduce the like-lihood of a mishap or accident resulting in a leak orspill to the environment. The correct use of DOT la-beling (per the MSDS) on all containers, trucks, andrail cars will enable emergency responders to reactproperly and quickly to any disaster thereby reducingthe potential risk to the environment and to personnel.

Storage of hydroquinone should be segregatedfrom incompatible chemicals to minimize the risk ofcross-contamination or contact. Buildings designatedfor storage should be equipped with appropriate fireprotection systems (alarms, sprinklers, emergencylighting, portable extinguishers).

If a spill or leak to the environment has occurred,fire department, emergency response and/or hazardousmaterials spill personnel should be notified immedi-ately. Cleanup should be attempted only by thosetrained in proper spill containment procedures. Con-taminated soils should be removed for incinerationand

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©1996 by CRC Press, Inc.

replaced with clean soil. If hydroquinone shouldcontact the water table, aquifer, or navigable water-way, cleanup should be started immediately. It ishighly soluble in water and total remediation may notbe possible. The local and/or state emergency re-sponse authorities must be notified. A comprehensiveemergency response or disaster preparedness/recoveryplan should be in place prior to any operations in-volving the use, transportation, storage, or disposal ofhydroquinone. If hydroquinone is spilled or leaked,the following specific steps are recommended:

; Restrict persons not wearing protective clothingfrom area of spill or leak until cleanup is com-plete and area can be opened for normal work.

; Remove all ignition sources.

; Ventilate area of leak.

; Collect powdered materials using a high-efficiency particulate air (HEPA) filter. Do NOTdry sweep (generates airborne dusts). Place inproper container for disposal. Absorb liquidscontaining hydroquinone in vermiculite, drysand, earth, or similar material and deposit insealed containers.

; It may be necessary to dispose of hydroquinoneas a hazardous waste. The responsible stateagency or the regional office of the federal Envi-ronmental Protection Agency (EPA) should becontacted for specific recommendations.

RISK ASSESSMENT: BUSINESSGeneral Assessment

Accidents or mishaps involving hydroquinone canpresent a significant threat to business operations. Themismanagement of chemical commodities can causepersonnel injuries and/or property damage/loss. Theloss or damage of equipment or facilities can signifi-cantly affect fiscal viability. Lawsuits that may resultfrom personnel injury/death, public exposures, and/orenvironmental contamination will also require a seri-ous expenditure of resources. Media attention sur-rounding an injury, death, or environmental damagecan also result in a loss of profits and loss of currentas well as future business prospects.

Always remember that anytime the terms“cancer,” “carcinogen,” or “reproductive hazard” areused, public emotion, hysteria, and ignorance can runequally high. This must be carefully consideredwhenever developing or implementing public relationspolicies.ÄÄ Recommended Risk-Reduction Measures

Company attorneys, safety and health professionals,and environmental specialists should be involved inthe development of any procedures dealing with safetyor emergency response. A company official should bepre-designated as a public relations officer with spe-cific training in dealing with the press. Corporateplans and policies should be developed, approved, andimplemented long before any need for such arises.

REFERENCESAmerican Conference of Governmental Industrial Hygienists. 1988.

Documentation of the Threshold Limit Values and Biological Ex-posure Indices, 5th Edition (with updates). Cincinnati: ACGIH

Bueche, J. R. 1972. Principles of Physics, 2nd Edition. New York:McGraw-Hill.

Calabrese, E. J. 1994. Biological Effects of Low Level Exposures. NewYork: CRC Press/Lewis Publishers.

Cockerman, L. G., B. S. Shane. 1994. Basic Environmental Toxicology.New York: CRC Press/Lewis Publishers.

Gardner, R. W. 1994. Chemical Intolerance. New York: CRCPress/Lewis Publishers.

Lauwerys, R. R., P. Hoet. 1993. Industrial Chemical Exposure. NewYork: CRC Press/Lewis Publishers.

Lewis, R. J., Sr. 1992. Sax's Dangerous Properties of Industrial Materi-als, Volumes 1, 2, and 3, 8th Edition. New York: Van NostrandReinhold.

Meyer, E. 1990. Chemistry of Hazardous Materials. Englewood Cliffs,NJ: Prentice Hall.

Patnaik, P. 1992. A Comprehensive Guide to the Hazardous Properties ofChemical Substances. New York: Van Nostrand Reinhold.

Proctor, N. H., J. P. Hughes. 1991. Chemical Hazards of the Workplace.New York: Van Nostrand Reinhold.

Quigley, D. R. 1994. Handbook of Emergency Chemical Management.New York: CRC Press/Lewis Publishers.

Rea, W. J. 1995. Chemical Sensitivity, Vol. I-III. New York: CRCPress/Lewis Publishers.

Richardson, M. 1995. Dictionary of Substance and Their Effects, Vol. I-VI. New York: CRC Press/Lewis Publishers.

Rylander, R., R. R. Jacobs. 1994. Organic Dusts. New York: CRCPress/Lewis Publishers.

Sacarello, H. L. A. 1994. The Comprehensive Handbook of HazardousMaterials. New York: CRC Press/Lewis Publishers.

Torkelson, T. R. V. K. Rowe. 1981. Halogenated aliphatic hydrocarbons.Patty’s Industrial Hygiene and Toxicology, Vol. 2B, Toxicology, pp3568-3572. New York: Wiley-Interscience.

U.S. Department of Health and Human Services, National Institute forOccupational Safety and Health. 1994. NIOSH Pocket Guide toChemical Hazards. Washington, D.C.: U.S. Government PrintingOffice.