The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of the Partnership included in the annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), filed with the SEC on March 2, 2021. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2020.

In March 2020, the FASB issued an accounting standards update to provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments in this update are effective for all entities as of March 12, 2020 through December 31, 2022. The Partnership is in the process of evaluating the2022 and are not expected to have a material impact that the new accounting guidance will have on the Partnership's consolidated financial position, results of operations and cash flows. Certain exceptions provided under this guidance may be applicable to future reference rate reform related transitions.

Depreciation expense on property, plant and equipment of $22,802$23,010 and $22,753$22,913 is included in cost of sales in the consolidated statements of operations for the three months ended March 31,September 30, 2021 and 2020, respectively. Depreciation expense on property, plant and equipment of $68,795 and $68,380 is included in cost of sales in the consolidated statements of operations for the nine months ended September 30, 2021 and 2020, respectively.

Amortization expense on other assets of $4,740$3,576 and $3,278$3,010 is included in costs of sales in the consolidated statements of operations for the three months ended March 31,September 30, 2021 and 2020, respectively. Amortization expense on other assets of $14,035 and $9,387 is included in costs of sales in the consolidated statements of operations for the nine months ended September 30, 2021 and 2020, respectively.

On May 3,November 1, 2021, the board of directors of Westlake Chemical Partners GP LLC ("Westlake GP"), the Partnership's general partner, declared a quarterly cash distribution for the three months ended March 31,September 30, 2021 of $0.4714 per unit. This distribution is payable on May 27,November 29, 2021 to unitholders of record as of May 13,November 12, 2021.

On October 4, 2018, the Partnership and Westlake Chemical Partners GP LLC, the general partner of the Partnership, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell the Partnership's common units, from time to time, up to an aggregate offering amount of $50,000. The Equity Distribution Agreement was amended on February 28, 2020 to reference a new shelf registration for utilization under this agreement. No common units were issued under this program as of March 31,September 30, 2021.

The Partnership and OpCo regularly enter into related party transactions with Westlake. See below for a description of transactions with related parties.

OpCo sells ethylene to Westlake under the Ethylene Sales Agreement. Additionally, the Partnership and OpCo from time to time provide other services or products for which it charges Westlake a fee.

DuringOpCo declared force majeure events in September 2021 during the Petro 2 facility turnaround, in June 2021 related to OpCo's Petro 1 facility outage, and in February and March 2021 due to the severe winter storm, OpCo's ethylene production facilities in the region experienced disruptions to their operations, resulting in lost production and additional maintenance and other costs. OpCo declared force majeure under the Ethylene Supply Agreement.storm. As a result of the force majeure,these events, the Partnership recognized aupdated its estimate of OpCo's 2021 anticipated production as of September 30, 2021. The buyer deficiency fee of $5,500 inis measured based upon the three months ended March 31, 2021, as a component of net sales, representing fixed margin and unavoided operating and maintenance capital expenditures and maintenance expenses during the force majeure events. The buyer deficiency is an estimate based on OpCo's anticipated 2021 ethylene production. Additionally, under the Ethylene Sales Agreement, if production costs billed to Westlake on an annual basis are less than 95%lower of the actual production costs incurred by OpCodeficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. Based upon this change in estimate of OpCo's 2021 anticipated production, the Partnership has recognized buyer deficiency fees and shortfall fees of $3,045 and $21,465 during the period, OpCo is entitled to recover the shortfall in the subsequent year. During the three and nine months ended March 31,September 30, 2021, based on the additional costs incurred during the force majeure events, the Partnership recognized arespectively. The buyer deficiency fees and shortfall of $4,178fees are classified as a component of net sales.

During 2020, the Lake Charles Petro 1 and Petro 2 facilities were impacted by Hurricanes Laura and Delta, which resulted in force majeure events under the Ethylene Sales Agreement. As a result of the force majeure events, the Partnership recognized a buyer deficiency fee of $69,555 as a component of net sales in 2020. Payment for the buyer deficiency fee was received by the Partnership in January 2021.

Charges for goods and services purchased by the Partnership and OpCo from Westlake and included in cost of sales relate primarily to feedstock purchased under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement.

Charges for services purchased by the Partnership from Westlake and included in selling, general and administrative expenses primarily relate to services Westlake performs on behalf of the Partnership under the Omnibus Agreement, including the Partnership's finance, legal, information technology, human resources, communication, ethics and compliance and other administrative functions.

Charges for goods and services purchased by the Partnership and OpCo from Westlake which were capitalized as assets relate primarily to the services of Westlake employees under the Services and Secondment Agreement.

On August 1, 2017, the Partnership, OpCo and Westlake executed an investment management agreement (the "Investment Management Agreement") that authorized Westlake to invest the Partnership's and OpCo's excess cash with Westlake for a term of up to a maximum of nine months. Per the terms of the Investment Management Agreement, the Partnership earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo. Accrued interest of $67$81 and $56 was included in the receivable under the Investment Management Agreement balance at March 31,September 30, 2021 and December 31, 2020, respectively. Total interest earned related to the Investment Management Agreement was $67$81 and $587$69 for the three months ended March 31,September 30, 2021 and 2020, respectively, and $225 and $876 for the nine months ended September 30, 2021 and 2020, respectively.

The Partnership's accounts receivable from Westlake result primarily from ethylene sales to Westlake and the buyer deficiency fee and the shortfall fee recognized under the Ethylene Sales Agreement, as discussed above under "Sales to Related Parties." The buyer deficiency fee and the shortfall fee recognized in the threenine months ended March 31,September 30, 2021 are scheduled to be received by the Partnership after the end of 2021.

The Partnership's accounts payable to Westlake result primarily from feedstock purchases under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement and the Omnibus Agreement.

OpCo is obligated to Westlake under various long-term and short-term noncancelable operating leases, primarily related to rail car leases and land. Operating lease rentals paid to Westlake for such leases were $686$997 and $670$407 for the three months ended March 31,September 30, 2021 and 2020, respectively, and $2,292 and $1,803 for the nine months ended September 30, 2021 and 2020, respectively, and reflected in other charges from Westlake that are included in cost of sales.

OpCo has 2 site lease agreements with Westlake, each of which has a term of 50 years. Pursuant to the site lease agreements, OpCo pays Westlake one dollar per site per year.

See Note 9 for a description of related party debt payable balances.

Interest on related party debt payable balances for the three months ended March 31,September 30, 2021 and 2020 was $2,236$2,190 and $3,950,$2,320, respectively. Interest on related party debt payable balances for the nine months ended September 30, 2021 and 2020 was $6,650 and $9,701, respectively. Interest on related party debt payable is presented as interest expense—Westlake in the consolidated statements of operations. At March 31,September 30, 2021 and December 31, 2020, accrued interest on related party debt was $2,236$2,193 and $2,336, respectively, and is reflected as a component of accrued liabilities in the consolidated balance sheets.

During the three months ended March 31,September 30, 2021 and 2020, Westlake accounted for approximately 82.0%84.3% and 85.7%93.9%, respectively, of the Partnership's net sales.

Long-term debt payable to Westlake consists of the following:

Accrued and other liabilities were $18,049$24,527 and $18,768 at March 31,September 30, 2021 and December 31, 2020, respectively. Accrued taxes, accrued maintenance expense, accrued turnaround costs and accrued interest,capital expenditures, which are components of accrued liabilities, were $3,120, $6,215$4,784, $5,438, $3,330 and $2,236,$4,832, respectively, at March 31,September 30, 2021 and $6,207, $3,905, $0 and $2,336,$2,286, respectively, at December 31, 2020. No other component of accrued and other liabilities was more than five percent of total current liabilities.

The non-cash investing activities related to accruals for capital expenditures were $582$3,663 and $20$1,945 for the threenine months ended March 31,September 30, 2021 and 2020, respectively.

This Management's Discussion and Analysis of Financial Condition and Results of Operations section should be read in conjunction with the accompanying consolidated financial statements and the notes thereto and the consolidated financial statements and notes thereto included in Westlake Chemical Partners LP's annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), as filed with the SEC on March 2, 2021. Unless otherwise indicated, references in this report to "we," "our," "us" or like terms, refer to Westlake Chemical Partners LP (the "Partnership"), Westlake Chemical OpCo LP ("OpCo") and Westlake Chemical OpCo GP LLC ("OpCo GP"). References to "Westlake" refer to Westlake Chemical Corporation and its consolidated subsidiaries other than the Partnership, OpCo GP and OpCo. The following discussion contains forward-looking statements. Please read "Forward-Looking Statements" for a discussion of limitations inherent in such statements.

We are a Delaware limited partnership formed by Westlake to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, we closed our initial public offering (the "IPO") of 12,937,500 common units. In connection with the IPO, we acquired a 10.6% interest in OpCo and a 100% interest in OpCo GP, which is the general partner of OpCo. On April 29, 2015, we purchased an additional 2.7% newly-issued limited partner interest in OpCo, resulting in an aggregate 13.3% limited partner interest in OpCo, effective April 1, 2015. The 12,686,115 subordinated units of the Partnership, all of which were previously owned by Westlake, were converted into common units of the Partnership on August 30, 2017. On September 29, 2017, we completed a secondary public offering of 5,175,000 common units and purchased an additional 5.0% newly-issued limited partner interest in OpCo, resulting in an aggregate 18.3% limited partner interest in OpCo, effective July 1, 2017. On March 29, 2019, we completed a private placement of 2,940,818 common units and used the net proceeds to purchase an additional 4.5% interest in OpCo, effective January 1, 2019, resulting in us owning an aggregate 22.8% limited partner interest in OpCo.

We generate revenue primarily by selling ethylene and the resulting co-products we produce. OpCo and Westlake have entered into an ethylene sales agreement (the "Ethylene Sales Agreement") pursuant to which we generate a substantial majority of our revenue. The Ethylene Sales Agreement is a long-term, fee-based agreement with a minimum purchase commitment and includes variable pricing based on OpCo's actual feedstock and natural gas costs and estimated other costs of producing ethylene (including OpCo's estimated operating costs and a five-year average of OpCo's expected future maintenance capital expenditures and other turnaround expenditures based on OpCo's planned ethylene production capacity for the year), plus a fixed margin per pound of $0.10 less revenue from co-products sales. Pursuant to the Ethylene Sales Agreement, Westlake's obligation to pay for the annual minimum commitment (95% of OpCo's budgeted ethylene production), which is measured on an annual basis, is not reduced for the first 45 days of a force majeure event, but is reduced for the portion of a force majeure event extending beyond the 45th day. In the event of a force majeure event, we recognize buyer deficiency fees representing fixed margin and unavoided operating and maintenance capital expenditures and maintenance expenses associated with ethylene that OpCo would have produced and is not expected to be produced based on anticipated production. Payment for the buyer deficiency fee is scheduled to be received by the Partnership after the conclusion of the year.

Our management seeks to maximize the profitability of our operations by effectively managing operating expenses, maintenance capital expenditures and turnaround costs. Our operating expenses are comprised primarily of feedstock costs and natural gas, labor expenses (including contractor services), utility costs (other than natural gas) and turnaround and maintenance expenses. With the exception of feedstock, including natural gas, and utilities-related expenses, operating expenses generally remain relatively stable across broad ranges of production volumes but can fluctuate from period to period depending on the circumstances, particularly maintenance and turnaround activities. Our maintenance capital expenditures and turnaround costs are comprised primarily of maintenance of our ethylene production facilities and the amortization of capitalized turnaround costs. These capital expenditures relate to the maintenance and integrity of our facilities. We capitalize the costs of major maintenance activities, or turnarounds, and amortize the costs over the period until the next planned turnaround of the affected facility.

The body of accounting principles generally accepted in the United States is commonly referred to as "GAAP." For this purpose, a non-GAAP financial measure is generally defined by the Securities and Exchange Commission ("SEC") as a numerical measure of a registrant's historical or future financial performance, financial position or cash flows that (1) excludes amounts, or is subject to adjustments that have the effect of excluding amounts, that are included in the most directly comparable measure calculated and presented in accordance with GAAP in the statement of income, balance sheet or statement of cash flows (or equivalent statements) of the registrant; or (2) includes amounts, or is subject to adjustments that have the effect of including amounts, that are excluded from the most directly comparable measure so calculated and presented. We use the non-GAAP measures of MLP distributable cash flow and EBITDA to analyze our performance. We define distributable cash flow as net income plus depreciation, amortization and disposition of property, plant and equipment, less contributions for turnaround reserves, maintenance capital expenditures and mark-to-market adjustment on derivative contracts. We define MLP distributable cash flow as distributable cash flow less distributable cash flow attributable to Westlake's noncontrolling interest in OpCo and distributions attributable to the incentive distribution rights holder. MLP distributable cash flow does not reflect changes in working capital balances. We define EBITDA as net income before interest expense, income taxes, depreciation and amortization. We use each of MLP distributable cash flow and EBITDA to analyze our performance. Fees for a buyer deficiency and Shortfall are included in net income in the periods in which they are recognized. MLP distributable cash flow and EBITDA are non-GAAP supplemental financial measures that management and external users of our consolidated financial statements, such as industry analysts, investors, lenders and rating agencies, may use to assess our operating performance as compared to other publicly-traded partnerships; our ability to incur and service debt and fund capital expenditures; and the viability of acquisitions and other capital expenditure projects and the returns on investment of various investment opportunities.

In September 2021, we commenced our response to this crisis has been the health and safetyplanned major maintenance activities, or turnaround, of our operators, who are seconded to us by Westlake, and those of our customers and vendors. Westlake has implemented preventative measures and developed corporate and regional response plans to minimize unnecessary risk of exposure. We and Westlake have modified certain business practices (including those related to employee travel, employee work locations and employee work practices) to conform to government restrictions and best practices encouraged by the Center for Disease Control and Prevention, the World Health Organization and other governmental and regulatory authorities. We and Westlake have implemented strategies to reduce costs, increase operational efficiencies and lower capital spending. We also deferred the planned turnaround at OpCo's Petro 2 ethylene unit in Lake Charles, Louisiana. The turnaround was originally expected to conclude in November. On September 27, 2021, shortly after the turnaround commenced, there was a flash fire at the quench tower of the Petro 2 facility. Several contractors working on the quench tower were injured. Although there was no sustained fire or offsite impact resulting from the incident and associated maintenance cost from 2020the quench tower did not sustain significant damage, due to the second halfsubsequent investigation by the Occupational Safety and Health Administration, the duration of 2021. Thethe turnaround has been extended and is now expected to last approximately 60 days.conclude in December. There are five lawsuits pending in connection with the flash fire.

InOpCo declared force majeure events in September 2021 during the Petro 2 facility turnaround, in June 2021 related to OpCo's Petro 1 facility outage, and in February 2021 large parts of the southern United States, including Louisiana and Kentucky, experienced a severe winter storm. Duedue to the severe winter storm, OpCo's ethylene production facilities in the region experienced disruption to their operations, resulting in lost production and additional maintenance costs. OpCo declared force majeure under the Ethylene Supply Agreement during February and March 2021.storm. As a result of thethese force majeure events we recognized a buyer deficiency feeand the commencement of $5.5 million and a Shortfall of $4.2 millionOpCo's Petro 2 ethylene unit turnaround in the first quarter ofSeptember 2021, that are scheduled to be received by the Partnership after the endupdated its estimate of OpCo's 2021 anticipated production as of September 30, 2021. The buyer deficiency fee is associated with ethylene that OpCo would have produced and is not expected to be produced in 2021measured based onupon the lower of the actual production deficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. Based upon this change in estimate of OpCo's 2021 anticipated production, facilities have since resumed production.the Partnership has recognized buyer deficiency fees and Shortfall of $3.0 million and $21.5 million during the three and nine months ended September 30, 2021, respectively. The buyer deficiency fees and Shortfall are classified as a component of net sales.