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  <xsd:element id="oln_EffectiveTaxRateDiscreteItemsnetPercent" name="EffectiveTaxRateDiscreteItemsnetPercent" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_EffectiveTaxRateUnremittedForeignEarningsinExcessofOnetimeTransitionTax" name="EffectiveTaxRateUnremittedForeignEarningsinExcessofOnetimeTransitionTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_EmployeeRelocationCostMember" name="EmployeeRelocationCostMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_EpoxySegmentMember" name="EpoxySegmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_EpoxyresinsMember" name="EpoxyresinsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_EstimatedCapitalSpendingForFacilityRelocation" name="EstimatedCapitalSpendingForFacilityRelocation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oln_EstimatedProjectCostForPlantRelocation" name="EstimatedProjectCostForPlantRelocation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oln_FacilityExitCostsAssetRetirementObligationsMember" name="FacilityExitCostsAssetRetirementObligationsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_FixedInterestRateSwaps1100MTranche1Member" name="FixedInterestRateSwaps1100MTranche1Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_FixedInterestRateSwaps400MTranche3Member" name="FixedInterestRateSwaps400MTranche3Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_FixedInterestRateSwaps900MTranche2Member" name="FixedInterestRateSwaps900MTranche2Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_ForeignCurrencyTranslationAdjustmentRollForward" name="ForeignCurrencyTranslationAdjustmentRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_ForeignExchangeContractLossMember" name="ForeignExchangeContractLossMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_ForwardContractsSellMember" name="ForwardContractsSellMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_FreeportProductSegmentProductionCapacityDecrease" name="FreeportProductSegmentProductionCapacityDecrease" nillable="true" substitutionGroup="xbrli:item" type="num:massItemType" xbrli:periodType="instant" />
  <xsd:element id="oln_GaininOtherOperatingIncomeduetoInsuranceRecoveries" name="GaininOtherOperatingIncomeduetoInsuranceRecoveries" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_GermanyMember" name="GermanyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_GovernmentGrantsforFacilityRelocationCapitalSpending" name="GovernmentGrantsforFacilityRelocationCapitalSpending" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oln_HendersonProductSegmentProductionCapacityDecrease" name="HendersonProductSegmentProductionCapacityDecrease" nillable="true" substitutionGroup="xbrli:item" type="num:massItemType" xbrli:periodType="instant" />
  <xsd:element id="oln_IncomeLossFromEquityMethodInvestmentsConsolidatingSubsidiaries" name="IncomeLossFromEquityMethodInvestmentsConsolidatingSubsidiaries" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_IncomeTaxAccountingStandardAdoption" name="IncomeTaxAccountingStandardAdoption" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_IncomeTaxReclassificationAdjustmentDerivativeContracts" name="IncomeTaxReclassificationAdjustmentDerivativeContracts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_IncomeTaxReclassificationAdjustmentForeignCurrencyTranslation" name="IncomeTaxReclassificationAdjustmentForeignCurrencyTranslation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_IncomeTaxReclassificationAdjustmentPensionandPostretirementBenefits" name="IncomeTaxReclassificationAdjustmentPensionandPostretirementBenefits" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_Incometaxreclassificationadjustment" name="Incometaxreclassificationadjustment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_IncreaseDecreaseinCapitalExpendituresIncurredbutNotYetPaid" name="IncreaseDecreaseinCapitalExpendituresIncurredbutNotYetPaid" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_IntercompanyFinancingActivities" name="IntercompanyFinancingActivities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_InterestRateContractLossMember" name="InterestRateContractLossMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_InterestRateSwapsDesignatedAsFairValueHedgesMember" name="InterestRateSwapsDesignatedAsFairValueHedgesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_LeadCommodityForwardContractsMember" name="LeadCommodityForwardContractsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_MilitaryandlawenforcementMember" name="MilitaryandlawenforcementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_NaturalGasCommodityForwardContractsMember" name="NaturalGasCommodityForwardContractsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_NiagaraProductSegmentProductionCapacity" name="NiagaraProductSegmentProductionCapacity" nillable="true" substitutionGroup="xbrli:item" type="num:massItemType" xbrli:periodType="instant" />
  <xsd:element id="oln_Nonoperatingpensionincome" name="Nonoperatingpensionincome" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_OtherComprehensiveIncomeLossNetGainLossRecognizedBeforeTax" name="OtherComprehensiveIncomeLossNetGainLossRecognizedBeforeTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_OtherComprehensiveIncomeLossReclassificationAdjustmentBeforeTax" name="OtherComprehensiveIncomeLossReclassificationAdjustmentBeforeTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oln_OtherCorporateAndUnallocatedCosts" name="OtherCorporateAndUnallocatedCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_OtherforeignMember" name="OtherforeignMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_Paymentsreceivedfromcustomersonsoldaccounts" name="Paymentsreceivedfromcustomersonsoldaccounts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_PensionAndOtherPostretirementBenefitsCurtailmentMember" name="PensionAndOtherPostretirementBenefitsCurtailmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_PensionAndPostretirementBenefitsSummaryRollForward" name="PensionAndPostretirementBenefitsSummaryRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_PensionIncomeExpense" name="PensionIncomeExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_PhenolicsandallylicsMember" name="PhenolicsandallylicsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_ProductSegmentProductionCapacityDecreaseIncrease" name="ProductSegmentProductionCapacityDecreaseIncrease" nillable="true" substitutionGroup="xbrli:item" type="num:massItemType" xbrli:periodType="instant" />
  <xsd:element id="oln_ReceivablesFinancingAgreementTerminyears" name="ReceivablesFinancingAgreementTerminyears" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_ReceivablesFinancingBorrowingAvailableCapacity" name="ReceivablesFinancingBorrowingAvailableCapacity" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oln_ReducedNiagaraSegmentProductionCapacity" name="ReducedNiagaraSegmentProductionCapacity" nillable="true" substitutionGroup="xbrli:item" type="num:massItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oln_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassLineItems" name="ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassTable" name="ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsByMajorClassTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_SecuredBorrowingMaximumCapacity" name="SecuredBorrowingMaximumCapacity" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="oln_SellingandAdministrationReclassificationASU201707" name="SellingandAdministrationReclassificationASU201707" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oln_SeniorCreditFacility" name="SeniorCreditFacility" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oln_SeniorTermLoanFacilityMember" name="SeniorTermLoanFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_ShareBasedCompensationArrangementByShareBasedPaymentAwardMarkToMarketAdjustment" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardMarkToMarketAdjustment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oln_ShareBasedCompensationArrangementByShareBasedPaymentAwardTotalExpense" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardTotalExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oln_Subfacilityofseniorcreditfacitility" name="Subfacilityofseniorcreditfacitility" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="oln_SumitomoCreditFacility" name="SumitomoCreditFacility" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationAbstract" name="SupplementalGuarantorFinancialInformationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationBalanceSheetsLineItems" name="SupplementalGuarantorFinancialInformationBalanceSheetsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationBalanceSheetsTable" name="SupplementalGuarantorFinancialInformationBalanceSheetsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_SupplementalGuarantorFinancialInformationBalanceSheetsTableTextBlock" name="SupplementalGuarantorFinancialInformationBalanceSheetsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationStatementofOperationsLineItems" name="SupplementalGuarantorFinancialInformationStatementofOperationsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationStatementofOperationsTable" name="SupplementalGuarantorFinancialInformationStatementofOperationsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_SupplementalGuarantorFinancialInformationStatementofOperationsTableTextBlock" name="SupplementalGuarantorFinancialInformationStatementofOperationsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationStatementsOfCashFlowsLineItems" name="SupplementalGuarantorFinancialInformationStatementsOfCashFlowsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationStatementsOfCashFlowsTable" name="SupplementalGuarantorFinancialInformationStatementsOfCashFlowsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_SupplementalGuarantorFinancialInformationStatementsOfCashFlowsTableTextBlock" name="SupplementalGuarantorFinancialInformationStatementsOfCashFlowsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationStatementsOfComprehensiveIncomeLineItems" name="SupplementalGuarantorFinancialInformationStatementsOfComprehensiveIncomeLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_SupplementalGuarantorFinancialInformationStatementsOfComprehensiveIncomeTable" name="SupplementalGuarantorFinancialInformationStatementsOfComprehensiveIncomeTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_SupplementalGuarantorFinancialInformationStatementsOfComprehensiveIncomeTableTextBlock" name="SupplementalGuarantorFinancialInformationStatementsOfComprehensiveIncomeTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_SupplementalGuarantorFinancialInformationTextBlock" name="SupplementalGuarantorFinancialInformationTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_SupplyContracts" name="SupplyContracts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oln_TaxRelatedReceivableNoncurrent" name="TaxRelatedReceivableNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oln_TheNetherlandsMember" name="TheNetherlandsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_TotalEnvironmentalIncomeExpense" name="TotalEnvironmentalIncomeExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oln_TotalProductSegmentProductionCapacityDecrease" name="TotalProductSegmentProductionCapacityDecrease" nillable="true" substitutionGroup="xbrli:item" type="num:massItemType" xbrli:periodType="instant" />
  <xsd:element id="oln_TransferofFinancialAssetsFacilityMaximum" name="TransferofFinancialAssetsFacilityMaximum" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oln_U.S.TaxCutsandJobsActProvisionalBenefit" name="U.S.TaxCutsandJobsActProvisionalBenefit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_UnrealizedGainsLossesOnDerivativeContractsSummaryRollForward" name="UnrealizedGainsLossesOnDerivativeContractsSummaryRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_WinchesterSegmentMember" name="WinchesterSegmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_WriteoffofEquipmentandFacilityMember" name="WriteoffofEquipmentandFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oln_Writeoffofunamortizeddeferreddebtissuancecosts" name="Writeoffofunamortizeddeferreddebtissuancecosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oln_ZincCommodityForwardContractsMember" name="ZincCommodityForwardContractsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>
