MATERIAL SAFETY DATA SHEETDUROCK Exterior Cement BoardMSDS #14-090-003Page 1 of 914090003SECTION 1CHEMICAL PRODUCT AND IDENTIFICATIONUnited States Gypsum Company550 West Adams StreetChicago, Illinois 60661-3637A Subsidiary of USG CorporationPRODUCT(S)Product Safety: 1 (800) 507-8899www.usg.comVersion Date: January 1, 2011Version: 6DUROCK Exterior Cement BoardCHEMICAL FAMILY /GENERAL CATEGORYCement BoardSYNONYMSWater-durable, mold-resistant panel for tile and other finishes in both interior and exteriorapplications.SECTION 2HAZARD IDENTIFICATIONEMERGENCY OVERVIEW:WARNING!This product is not expected to produce any unusual hazards during normal use. Exposure to high dust levels mayirritate the skin, eyes, nose, throat, or upper respiratory tract. Portland cement is a nuisance dust. However, portlandcement is strongly alkaline and can cause severe injury. Contact with eyes or skin can cause irritation and possibleirreversible tissue damage, corrosion damage, chemical burning and corneal damage. Wear eye and skin protection.POTENTIAL HEALTH EFFECTS (See Section 11 for more information)ACUTE :InhalationExposure to dust generated during the handling or use of the product may cause temporary irritationto eyes, skin, nose, throat, and upper respiratory tract. Persons subjected to large amounts of thisdust will be forced to leave area because of nuisance conditions such as coughing, sneezing andnasal irritation. Labored breathing may occur after excessive inhalation. If respiratory symptomspersist, consult physician. Inhalation of portland cement dust can irritate or burn the nose, throat, andmucous membrane of the upper respiratory tract. Signs of excessive exposure to this dust includeshortness of breath and reduced pulmonary function. If respiratory symptoms persist, consultphysician.EyesDust can cause temporary mechanical irritation of eyes. If burning, redness, itching, pain or othersymptoms persist or develop, consult physician. Portland Cement is a strongly alkaline material and isvery irritating to eyes. The extent of damage depends on duration of contact. Rapid response is veryimportant to prevent significant damage to the eye (See Section 4, First Aid Measures). Portlandcement can cause burns and cornea damage that may result in permanent damage with risk ofblindness. Contact lenses should not be worn when working with portland cement. If burning,redness, itching, pain or other symptoms persist or develop, consult physician.SkinNone known.IngestionNone known.CHRONIC:InhalationExposures to respirable crystalline silica are not expected during the normal use of this product;however, actual levels must be determined by workplace hygiene testing. Prolonged and repeatedexposure to airborne free respirable crystalline silica can result in lung disease (i.e., silicosis) and/or

MATERIAL SAFETY DATA SHEETMSDS #14-090-003Page 2 of 9DUROCK Exterior Cement Boardlung cancer. The development of silicosis may increase the risks of additional health effects. The riskof developing silicosis is dependent upon the exposure intensity and duration.EyesNone known.SkinNone known.IngestionNone known.TARGET ORGANS: Eyes, skin and respiratory system.PRIMARY ROUTES OF ENTRY: Inhalation, eyes and skin contact.CARCINOGENICITY CLASSIFICATION OF INGREDIENT(S) All substances listed are associated with the nature ofthe raw materials used in the manufacture of this product and are not independent components of the productformulation. All substances, if present, are at levels well below regulatory limits. See Section 11: ToxicologyInformation for detailed information.MATERIALIARCFiber Glass ScrimCrystalline silica31NTPACGIH21A3A2CAL- 65Not ListedListedIARC - International Agency for Research on Cancer: 1- Carcinogenic to humans; 2A – Probably carcinogenic tohumans; 2B – Possibly carcinogenic to humans; 3 - Not classifiable as a carcinogen; 4 – Probably not a carcinogenNTP – National Toxicology Program (Health and Human Services Dept., Public Health Service, NIH/NIEHS): 1Known to be carcinogen; 2- Anticipated to be carcinogensACGIH – American Conference of Governmental Industrial Hygienists: A1 – Confirmed human carcinogen; A2 –Suspected human carcinogen; A3 – Animal carcinogen; A4 - Not classifiable as a carcinogen; A5 – Not suspected asa human carcinogenCAL-65 – California Proposition 65 “Chemicals known to the State of California to Cause Cancer”Respirable crystalline silica: IARC: Group 1 carcinogen, NTP: Known human carcinogen. The weight percent ofcrystalline silica given represents total quartz and not the respirable fraction. The weight percent of respirable silicahas not been measured in this product.POTENTIAL ENVIRONMENTAL EFFECTS: Portland cement is expected to be toxic to fish due to its high alkalinity(pH 12). Discharge of large quantities directly into waterways would be expected to cause significant fish kills. (SeeSection 12 for more information.)SECTION 3COMPOSITION, INFORMATION ON INGREDIENTSMATERIALPortland CementExpanded Clay AggregateOr Expanded ShaleHigh Alumina CementFly AshGypsum (CaSO4 2H2O)Fiber Glass ScrimSoda AshCrystalline SilicaWT%10-3030-500-1010-200-101-50-2 5CAS 813397-24-565997-17-3497-19-814808-60-7 All ingredients of this product are included in the U.S. Environmental Protection Agency’s Toxic Substances ControlAct Chemical Substance Inventory and the Canadian Domestic Substances List (DSL). The weight percent for silica represents total quartz and not the respirable fraction.

MATERIAL SAFETY DATA SHEETMSDS #14-090-003Page 3 of 9DUROCK Exterior Cement BoardSECTION 4FIRST AID MEASURESFIRST AID PROCEDURESInhalationRemove to fresh air. Leave the area of exposure and remain away until coughing and other symptomssubside. Other measures are usually not necessary, however if conditions warrant, contact physician.EyesIn case of contact, do not rub or scratch your eyes. Due to portland cement content in this product, ifeye contact occurs immediately flush eyes with copious amounts of water, occasionally lifting the lowerand upper lids. Get medical attention immediately. Contact lenses should not be worn when workingwith this material.SkinBecause of the potential of chemical burns due to the portland cement content of this product, flushexposed skin with copious amounts of water for at least 15 minutes depending on concentration,amount and duration of exposure. Wash with mild soap and water. Immediately remove allcontaminated clothing, including footwear. Launder clothing before reuse. If irritation or pain persistsget medical attention immediately. A commercially available hand lotion may be used to treat dry skinareas. If skin has become cracked, take appropriate action to prevent infection and promote healing. Ifirritation persists, consult physician.IngestionDue to the alkalinity caused by the portland cement content of this product, get medical attentionimmediately.MEDICAL CONDITIONS WHICH MAY BE AGGRAVATED: Pre-existing upper respiratory and lung diseases suchas, but not limited to, bronchitis, emphysema and asthma. Pre-existing skin diseases such as, but not limited to,rashes and dermatitis. Some individuals with unusual hypersensitivity to hexavalent chromium (chromium 6) saltsmay exhibit an allergic response to portland cement, due to trace amounts of chromium in the portland cement. Theresponse may appear in a variety of forms ranging from a mild rash to severe skin ulcers. Sensitized individuals mayreact immediately upon contact and others may first experience this effect after years of contact with portland cementproducts.NOTES TO PHYSICIAN: Skin irritation may occur hours or days after the time of portland cement exposure. Themain types of skin reactions seen are dermatitis of the hands, forearms, and feet seborrheic eczema, stasisdermatitis, and, occasionally exfoliative dermatitis.SECTION 5FIRE FIGHTING MEASURESGeneral Fire HazardsNone knownExtinguishing MediaWater or use extinguishing media appropriate for surrounding fire.Special Fire Fighting ProceduresWear appropriate personal protective equipment. See section 8.Unusual Fire/ Explosion HazardsNone knownHazardous Combustion ProductsNone knownFlash PointNot ApplicableAuto IgnitionNot ApplicableMethod UsedNot ApplicableUpper Flammable Limit (UFL)Not DeterminedFlammabilityClassificationNot ApplicableLower Flammable Limit (LFL)Not DeterminedRate of BurningNot Applicable

MATERIAL SAFETY DATA SHEETMSDS #14-090-003Page 4 of 9DUROCK Exterior Cement BoardSECTION 6ACCIDENTAL RELEASE MEASURESCONTAINMENT: Collect panels from spillage and if not damaged or contaminated by foreign material, panels may bereclaimed.CLEAN-UP: Use normal clean up procedures. No special precautions.DISPOSAL: Follow all local, state, provincial and federal regulations. Never discharge large releases directly intosewers or surface waters.SECTION 7HANDLING AND STORAGEHANDLING: Avoid dust contact with eyes and skin. Wear the appropriate eye and skin protection against dust (SeeSection 8). Minimize dust generation and accumulation. Avoid breathing dust. Wear the appropriate respiratoryprotection against dust in poorly ventilated areas and if TLV is exceeded (see Sections 2 and 8). Use good safety andindustrial hygiene practices. When moving board with a forklift or similar equipment, it is essential that the equipmentbe rated capable of handling the loads. The forks should always be long enough to extend completely through thewidth of the load. Fork spacing between supports should be one half the length of the panels or base being handledso that a maximum of 4’ extends beyond the supports on either end.Cement panels are very heavy awkward loads posing the risk of severe back injury. Use proper lifting techniques.STORAGE: Store in a cool, dry, ventilated area away from sources of heat, moisture and incompatibilities (seeSection 10). Protect product from physical damage.Protect from weather and prevent exposure to sustained moisture.Storing board flat will prevent the potential safety hazards of the board falling over. However, in other situations,storing the board flat may cause a tripping hazard or exceed floor limit loads.SECTION 8EXPOSURE CONTROLS/PERSONAL PROTECTIONMATERIALPortland CementExpanded Clay AggregateOr Expanded ShaleHigh Alumina CementFly AshGypsum (CaSO4 2H2O)Fiber Glass ScrimSoda AshCrystalline SilicaWT%10-3030-500-1010-200-101-50-2 53TLV (mg/m )10(NE)(NE)10(T)10101 f/cc(R)*10(T)0.025(R)(T)–Total; (R)–Respirable; (NE)-Not Established; (C)-Ceiling; (STEL)-Short-term exposure limit(F)-Fume; (Du)-Dust; (M)-Mistppm-part per million; f/cc-fiber per cubic centimeter; mppcf- million particles per cubic foot3PEL( mg/m 5(T)/5(R)15(T)/5(R)0.1(R)

MATERIAL SAFETY DATA SHEETMSDS #14-090-003Page 5 of 9DUROCK Exterior Cement Board*ACGIH: 1 fiber/cubic centimeter air for fibers longer than 5 micrometers and thinner than 3 micrometers.ENGINEERING CONTROLS: Provide ventilation sufficient to control airborne dust levels. If user operations generateairborne dust, use ventilation to keep dust concentrations below permissible exposure limits. Where generalventilation is inadequate, use process enclosures, local exhaust ventilation, or other engineering controls to controldust levels below permissible exposure limits.RESPIRATORY PROTECTION: Wear a NIOSH/MSHA-approved respirator equipped with particulate cartridges whendusty in poorly ventilated areas, and if TLV is exceeded. A respiratory program that meets OSHA's 29 CFR 1910.134and ANSI Z88.2 requirements must be followed whenever workplace conditions warrant a respirator's use. Ifengineering controls are not possible, wear a properly fitted NIOSH/MSHA-approved particulate respirator.OTHER PERSONAL PROTECTIVE EQUIPMENT:Eye/FaceDue to portland cement content in this porduct, wear safety glasses with side shields or goggles for eyeprotection to avoid irritation and severe chemical burns of the eye. Facilities storing or using thismaterial should be equipped with an adequate number of eyewash facilities and safety showers.Contact lenses should not be worn when working with portland cement.SkinWear gloves and protective clothing to prevent repeated or prolonged skin contact.GeneralSelection of Personal Protective Equipment will depend on environmental working conditions andoperations.SECTION 9PHYSICAL AND CHEMICAL PROPERTIESAppearanceGrayVapor Density (Air 1)Not ApplicableOdorLow to no odorSpecific Gravity (H2O 1)1.2Odor ThresholdNot DeterminedSolubility in water (g/100g)Not DeterminedPhysical StateSolid (board)Partition CoefficientNot ApplicablepH @ 25 º C 12Auto-ignition TempNot DeterminedMelting PointNot ApplicableDecomposition TempNot DeterminedFreezing PointNot ApplicableViscosityNot ApplicableBoiling PointNot ApplicableParticle SizeVariesFlash PointNot ApplicableBulk Density 2-3 lb/ft2 / 9-15 kg/m2Evaporation Rate (BuAc 1)Not ApplicableMolecular WeightMixtureUpper Flammable Limit (UFL)Not DeterminedVOC ContentZero g/LLower Flammable Limit (LFL)Not DeterminedPercent VolatileZeroVapor Pressure (mm Hg)Not ApplicableSECTION 10CHEMICAL STABILITY AND REACTIVITYSTABILITYStable.CONDITIONS TO AVOIDContact with incompatibles (see below).

MATERIAL SAFETY DATA SHEETDUROCK Exterior Cement BoardINCOMPATIBILITYNone known.HAZARDOUS POLYMERIZATIONNone known.HAZARDOUS DECOMPOSITIONNone known.MSDS #14-090-003Page 6 of 9SECTION 11TOXICOLOGICAL INFORMATIONACUTE EFFECTS: None known.CHRONIC EFFECTS / CARCINOGENICITY:Crystalline Silica: Exposures to respirable crystalline silica are not expected during the normal use of this product;however, actual levels must be determined by workplace hygiene testing. The weight percent of respirable crystallinesilica may not have been measured in this product. Prolonged and repeated exposure to airborne free respirablecrystalline silica can result in lung disease (i.e., silicosis) and/or lung cancer. The developmen