Exhibit 99.1

Trinseo Reports Second Quarter 2014 Financial Results

Second Quarter 2014 Highlights

BERWYN, Pa – August 6, 2014 – Trinseo (NYSE: TSE), a global materials company and manufacturer of plastics, latex and rubber, today reported its Second Quarter of 2014 financial results with revenue of $1,341 million and Adjusted EBITDA of $79 million.

“We had another solid quarter of results,” said Chris Pappas, Trinseo President and Chief Executive Officer. “The Emulsion Polymers Division benefitted from the improving tire market in combination with our differentiated product strategy, and we delivered stronger volumes in latex to the carpet, performance latex and Asia paper markets. In Plastics, styrenic polymers volumes were up due to the peak appliance season and polycarbonate margins improved after a low first quarter.”

Commenting on the Company’s other initiatives, Pappas added, “I am proud of our many achievements during the Second Quarter of 2014, including our successful IPO in June which enabled us to reduce our long-term debt by 10% in July 2014. In addition, we announced changes to our polycarbonate business structure, which are expected to result in substantial improvements for the Fourth Quarter 2014 and beyond. Our team remains extremely focused on executing our strategy and delivering value to shareholders.”

1

Revenue in the Second Quarter decreased 2% versus the prior year driven by a 5% reduction in price, which was primarily driven by the pass through of lower styrene and butadiene costs. This was partially offset by a favorable foreign exchange impact as the US dollar weakened compared to the Euro. Sequentially, revenue decreased 1% due to the pass through of lower styrene cost and lower styrene monomer related sales.

Adjusted EBITDA for the quarter increased $36 million, or 84%, versus the prior year. This increase was driven primarily by the impact of inventory revaluation which had an unfavorable impact of $26 million in the prior year as compared to a favorable $3 million impact in the current year. In addition, prior year results included an $8 million foreign exchange loss compared to a $2 million gain in the current year. Sequentially, Adjusted EBITDA decreased $9 million, or 10%, due primarily to lower JV earnings.

Second Quarter Results by Business Segment

2

Free Cash Flow and Liquidity

On July 14 we used the proceeds from our IPO to repay $132.5 million face amount of our Senior Secured Notes due 2019 at a redemption price equal to 103% of the principal amount, plus accrued and unpaid interest. Free cash flow was breakeven for the Second Quarter, which included $56 million in termination payments related to the Dow Emerging Markets Latex JV Option and the Bain Advisory Agreement. Quarter-end liquidity was $675 million excluding the cash that was subsequently used to pay down the notes, including the related call premium and accrued interest.

Outlook

Commenting on the outlook for the balance of 2014 Pappas said, “In aggregate we see the 2014 year end Adjusted EBITDA comfortably ahead of 2013. The third quarter of 2014 will have some challenges, notably by the summer slowdown in Europe, an outage driven Benzene price spike, our ESBR rubber turnaround and a short unplanned outage at our rubber site in July. However, all of these items should be behind us by the end of September and we expect a strong fourth quarter as these factors give way to moderating Benzene costs, rebounding Polycarbonate margins and continued solid Rubber and Latex performance.”

Conference Call and Webcast Information

Trinseo will host a conference call to discuss its Second Quarter of 2014 financial results tomorrow, Thursday, August 7, 2014 at 11 AM Eastern Time.

Commenting on results will be Trinseo’s Chris Pappas, President and Chief Executive Officer, John Feenan, Executive Vice President and Chief Financial Officer and David Stasse, Vice President, Treasury and Investor Relations. The conference call will be available by phone at:

Participant Toll-Free Dial-In Number: 877-372-0878

Participant International Dial-In Number: +1 253-237-1169

Conference ID / passcode: 80555507

The Company will also offer a live, listen-only Webcast of the conference call on the Trinseo Investor relations website.

Trinseo has posted its Second Quarter of 2014 financial results on the Company’s Investor Relations website. The presentation slides will also be made available in the webcast player prior to the conference call. The Company will also furnish copies of the financial results press release and presentation slides to investors by means of a Form 8-K filing with the U.S. Securities and Exchange Commission (SEC).

A replay of the conference call and transcript will be archived on the Company’s Investor Relations website shortly following the conference call. The replay will be available until August 7, 2015.

Formerly known as Styron, Trinseo previously announced plans to change the name of all Styron affiliated companies to Trinseo. Some, but not all, of the Styron companies have completed the name change process and are currently known as Trinseo; Styron companies that have not completed this process will continue to do business as Styron until their respective name changes are complete. Styron’s operating companies also continue to do business as Styron at this time.

3

About Trinseo

Trinseo (NYSE:TSE) is a global materials company and manufacturer of plastics, latex and rubber. Trinseo’s technology is used by customers in industries such as home appliances, automotive, building & construction, carpet, consumer electronics, consumer goods, electrical & lighting, medical, packaging, paper & paperboard, rubber goods and tires.

Use of non-GAAP measures

Trinseo management believes that measures of income excluding certain items (“non-GAAP” measures) provide relevant and meaningful information to investors about the ongoing operating results of the Company. Such measurements are not recognized in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and should not be viewed as an alternative to GAAP measures of performance. Reconciliations of non-GAAP measures to GAAP measures are provided in the Notes to Condensed Consolidated Financial Information.

Note on Forward-Looking Statements

This press release may contain “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Words such as “expect,” “estimate,” “project,” “budget,” “forecast,” “anticipate,” “intend,” “plan,” “may,” “will,” “could,” “should,” “believes,” “predicts,” “potential,” “continue,” and similar expressions are intended to identify such forward-looking statements. Forward-looking statements in this press release may include, without limitation, forecasts of growth, revenues, business activity, acquisitions, financings and other matters that involve known and unknown risks, uncertainties and other factors that may cause results, levels of activity, performance or achievements to differ materially from results expressed or implied by this press release. Such risk factors include, among others: conditions in the global economy and capital markets, volatility in costs or disruption in the supply of the raw materials utilized for our products; loss of market share to other producers of styrene-based chemical products; compliance with environmental, health and safety laws; changes in laws and regulations applicable to our business; our inability to continue technological innovation and successful introduction of new products; system security risk issues that could disrupt our internal operations or information technology services; and the loss of customers. Additional risks and uncertainties are set forth in the Company’s reports filed with the United States Securities and Exchange Commission, which are available at http://www.sec.gov/ as well as the Company’s web site at http://www.trinseo.com. As a result of the foregoing considerations, you are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. All forward-looking statements are qualified in their entirety by this cautionary statement. The Company undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

4

TRINSEO S.A.

Condensed Consolidated Statements of Operations

(In thousands, except per share data)

(Unaudited)

5

TRINSEO S.A.

Condensed Consolidated Balance Sheets

(In thousands, except per share data)

(Unaudited)

6

TRINSEO S.A.

Condensed Consolidated Statements of Cash Flows

(In thousands)

(Unaudited)

7

TRINSEO S.A.

Notes to Condensed Consolidated Financial Information

(Unaudited)

Note 1: Revenue by Segment

8

Note 2: Reconciliation of Non-GAAP Performance Measures to Net Income (Loss)

EBITDA is a non-GAAP financial measure that we refer to in making operating decisions because we believe it provides meaningful supplemental information regarding the Company’s operational performance. We present EBITDA because we believe that it is useful for investors to analyze disclosures of our operating results on the same basis as that used by our management. We believe the use of EBITDA as a metric assists our board of directors, management and investors in comparing our operating performance on a consistent basis because it removes the impact of our capital structure (such as interest expense), asset base (such as depreciation and amortization) and tax structure.

We also believe that the presentation of Adjusted EBITDA and Adjusted EBITDA excluding inventory revaluation provides investors with a useful analytical indicator of our performance and of our ability to service our indebtedness. We define Adjusted EBITDA as income (loss) from continuing operations before interest expense, net; income tax provision; depreciation and amortization expense; loss on extinguishment of long-term debt; asset impairment charges; advisory fees paid to affiliates of Bain Capital; gains or losses on the dispositions of businesses and assets; restructuring and other non-recurring items.

We present Adjusted EBITDA excluding inventory revaluation in order to facilitate the comparability of results from period to period by adjusting cost of sales to reflect the cost of raw material during the period, which is often referred to as the replacement cost method of inventory valuation. We believe this measure minimizes the impact of raw material purchase price volatility in evaluating our performance. Our approach to calculating inventory revaluation is intended to represent the difference between the results under the FIFO and the replacement cost methods. However, our calculation could differ from the replacement cost method if the monthly raw material standards are different from the actual raw material prices during the month and production and purchase volumes differ from sales volumes during the month. These factors could have a significant impact on the inventory revaluation calculation.

Lastly, we present Adjusted Net Income (Loss) and Adjusted EPS as additional performance measures. Adjusted Net Income (loss) is calculated as Adjusted EBITDA (defined beginning with Net Income (loss), above), less interest expense, less the provision for income taxes and depreciation and amortization, tax affected for various discrete items, as appropriate. Adjusted EPS is calculated as Adjusted Net Income per weighted average diluted shares outstanding for a given period. We believe that Adjusted Net Income and EPS provide transparent and useful information to management, investors, analysts and other parties in evaluating and assessing our core operating results from period-to-period after removing the impact of unusual, non-operational or restructuring-related activities that affect comparability.

There are limitations to using financial measures such as EBITDA, Adjusted EBITDA, Adjusted EBITDA excluding inventory revaluation, Adjusted Net Income, and Adjusted EPS. These performance measures are not intended to represent cash flow from operations as defined by GAAP and should not be used as alternatives to net income as indicators of operating performance or to cash flow as measures of liquidity. Other companies in our industry may use these performance measures differently than we do. As a result, it may be difficult to use these or similarly-named financial measures that other companies may use, to compare the performance of those companies to our performance. We compensate for these limitations by providing reconciliations of these performance measures to our net income (loss), which is determined in accordance with U.S. GAAP.

9

Note 3: Defining Certain Liquidity Measures

The Company uses a number of measures to evaluate and discuss its liquidity position and performance, including Free Cash Flow and Liquidity. Free Cash Flow is defined as cash from both operating and investing activities, less the impact of changes in restricted cash. Liquidity is defined as total cash and cash equivalents plus unused borrowing capacity on the Company’s revolving debt and accounts receivable securitization facility.

Free Cash Flow and Liquidity are not intended to represent cash flows from operations as defined by GAAP, and therefore, should not be used as an alternative for that measure. Other companies in our industry may define Free Cash Flow and Liquidity differently than we do. As a result, it may be difficult to use these or similarly-named financial measures that other companies may use, to compare the performance of those companies to our performance. The Company compensates for these limitations by providing the following detail, which is determined in accordance with U.S. GAAP and the terms of related borrowing agreements.

10

The following provides further detail of how these amounts are derived for the periods discussed herein:

Free Cash Flow

Note: free cash flow for the three and six months ended June 30, 2014, includes $56 million outflow resulting from the termination of our Latex JV Option Agreement with Dow and our Advisory Agreement with Bain Capital.

Liquidity

11