Exhibit 99.1

STERIS CORPORATION

NEWS ANNOUNCEMENT

FOR IMMEDIATE RELEASE

STERIS CORPORATION ANNOUNCES FISCAL 2013 SECOND QUARTER RESULTS

Mentor, Ohio (October 31, 2012)—STERIS Corporation (NYSE: STE) today announced financial results for its fiscal 2013 second quarter ended September 30, 2012. Included in the financial results is a $21.5 million pre-tax adjustment, based on actual experience through the second quarter, of the SYSTEM 1 Rebate Program liability. As reported, fiscal 2013 second quarter revenue was $356.3 million compared with $342.7 million in the second quarter of fiscal 2012. Operating income for the second quarter was $62.3 million compared with $47.6 million in the second quarter of fiscal 2012. Net income was $40.1 million, or $0.68 per diluted share, compared with net income of $29.6 million, or $0.50 per diluted share in the second quarter of fiscal 2012.

Of the $21.5 million pre-tax adjustment, $20.4 million is attributable to the Customer Rebate portion of the Program and was recorded as an increase to revenue, and $1.1 million is attributable to the disposal costs of SYSTEM 1 units to be returned and was recorded as a reduction to cost of revenue. Adjusted revenue excludes the $20.4 million Rebate Program adjustment. Adjusted net income and adjusted diluted earnings per share exclude the impact of the SYSTEM 1 Rebate Program, amortization of purchased intangible assets, acquisition related transaction and integration costs, and certain other items identified in the attached table to provide comparative analysis.

Adjusted revenue for the second quarter of fiscal 2013 was $335.9 million, a decline of 2% compared to the second quarter of fiscal 2012. Adjusted net income for the second quarter of fiscal 2013 was $31.0 million, or $0.53 per diluted share, the same as adjusted net income for the second quarter of fiscal 2012.

“We are pleased with the performance of our business for the first half of the fiscal year,” said Walt Rosebrough, President and Chief Executive Officer of STERIS. “During the second quarter, we experienced softening in our international revenue which was offset by demand in the U.S. Excluding the impact from SYSTEM 1E, we had solid organic revenue growth in our Healthcare segment in the U.S., with strength in several new product areas. Our integration of the U.S. Endoscopy acquisition is on schedule and is performing in-line with our expectations.”

STERIS Corporation

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Segment Results

As reported, Healthcare revenue in the quarter was $256.8 million compared with $243.2 million in the same period last year. Adjusted revenue was $236.4 million in the second quarter of fiscal 2013, down 3% from the prior year. Contributing to the quarter, consumable revenue grew 12% and service revenue grew 2%, while capital equipment revenue declined 11%, primarily due to comparison with the ramp-up of SYSTEM 1E during the prior year. The performance of the Healthcare consumable franchise reflected a combination of good performance from U.S. Endoscopy, which closed on August 15, 2012, and other consumables offset by continued declines in S20 sterilant. Regarding capital equipment, excluding SYSTEM 1E unit sales, capital equipment revenue grew 2%, with good performance in the U.S. offset by weakness internationally. As reported, segment operating income was $42.1 million compared with $28.0 million in last year’s second quarter. Adjusted segment operating income was $26.7 million in the second quarter of fiscal 2013 compared with $29.8 million in the same period last year. The decline in adjusted segment operating income year-over-year was the result of lower revenue attainment due to the impact of the phase out of S20 sterilant and the expected post-transition decline in SYSTEM 1E unit sales.

Life Sciences second quarter revenue declined 7% to $54.6 million compared with $58.9 million in the second quarter of fiscal 2012. Consumable revenue grew 5% and service revenue increased 1% while capital equipment revenue declined 24%. The Company believes that the decline in capital equipment revenue is due to timing, as shipments within the segment tend to vary from quarter to quarter. Life Sciences operating income was $10.5 million, or 19.3% of revenue, compared with $11.1 million, or 18.8% of revenue, in the same period last year. The improvement in operating margin is primarily attributable to the mix shift in the business toward recurring revenue.

Fiscal 2013 second quarter revenue for Isomedix Services was $44.3 million compared with $40.0 million in the same period last year, an increase of 11%. Revenue benefitted from increased volumes from core medical device Customers as well as the acquisition of Biotest in March 2012. Operating income was $12.7 million in the quarter compared with $11.2 million in the second quarter of last year.

STERIS Corporation

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Cash Flow

Net cash provided by operations for the six months of fiscal 2013 was $112.0 million, compared with $60.5 million last year. Free cash flow (see note 1) for the first half of fiscal 2013 was $67.0 million, compared with $26.1 million in the prior year. The improvement in free cash flow is primarily due to improvements in working capital management, specifically the anticipated reduction of over $20 million in SYSTEM 1E related inventory and lower days sales outstanding.

Dividend Announcement

The Company also announced today that STERIS’s Board of Directors has authorized a quarterly dividend of $0.19 per common share. The dividend is payable December 19, 2012 to shareholders of record at the close of business on November 21, 2012.

Outlook

As a result of recent acquisitions as well as the Rebate Program reversal in the quarter, the Company will only be providing adjusted guidance going forward. Adjusted revenue and adjusted earnings per diluted share exclude the impact of the SYSTEM 1 Rebate Program, amortization of purchased intangible assets, acquisition related transaction and integration costs, and certain other items to provide comparative analysis.

The Company’s expectations for both adjusted revenue and adjusted earnings per diluted share remain unchanged for fiscal 2013: total Company adjusted revenue growth for fiscal 2013 in the range of 3-4% and adjusted earnings per diluted share in the range of $2.15 to $2.35.

The Company’s outlook for fiscal 2013 reflects certain key assumptions, some of which are listed below:

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For the full fiscal year 2013, free cash flow (see note 1) is anticipated to be approximately $130 million excluding the SYSTEM 1 Rebate Program and class action settlement, or $100 million including those items. Capital expenditures are anticipated to be approximately $95 million, as the Company is investing in several major projects within its facilities that are designed to improve quality, reduce cost and add value to our current product offering.

Conference Call

In conjunction with this release, STERIS Corporation management will host a conference call today at 10:00 a.m. Eastern time. The conference call can be heard live over the Internet at www.steris-ir.com or via phone by dialing 1- 800-369-8428 in the United States and Canada, and 1-773-799-3378 internationally, then referencing the password “STERIS”.

For those unable to listen to the conference call live, a replay will be available beginning at 12:00 p.m. Eastern time on October 31, 2012, either over the Internet at www.steris-ir.com or via phone by calling 1- 866-501-0069 in the United States and Canada, or 1- 203-369-1813 internationally.

About STERIS

The mission of STERIS Corporation is to provide a healthier today and safer tomorrow through knowledgeable people and innovative infection prevention, decontamination and health science technologies, products and services. The Company has approximately 6,000 dedicated employees around the world working together to supply a broad array of solutions by offering a combination of equipment, consumables and services to healthcare, pharmaceutical, industrial and government Customers. The Company is listed on the New York Stock Exchange under the symbol STE. For more information, visit www.steris.com.

(1) Free cash flow is a non-GAAP number used by the Company as a measure to gauge its ability to fund future principal debt repayments, growth outside of core operations, repurchase common shares, and pay cash dividends. STERIS defines free cash flow as net cash flows from operating activities less purchases of property, plant, equipment and intangibles plus proceeds from the sale of property, plant, equipment and intangibles. STERIS’s calculation of free cash flow may vary from other companies. Please see the attached financial tables for a complete reconciliation of these non-GAAP numbers to the nearest GAAP information.

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This press release and the referenced conference call may contain statements concerning certain trends, expectations, forecasts, estimates, or other forward-looking information affecting or relating to the Company or its industry, products or activities that are intended to qualify for the protections afforded “forward-looking statements” under the Private Securities Litigation Reform Act of 1995 and other laws and regulations. Forward-looking statements speak only as to the date of this press release, and may be identified by the use of forward-looking terms such as “may,” “will,” “expects,” “believes,” “anticipates,” “plans,” “estimates,” “projects,” “targets,” “forecasts,” “outlook,” “impact,” “potential,” “confidence,” “improve,” “optimistic,” “deliver,” “comfortable,” “trend”, and “seeks,” or the negative of such terms or other variations on such terms or comparable terminology. Many important factors could cause actual results to differ materially from those in the forward-looking statements including, without limitation, disruption of production or supplies, changes in market conditions, political events, pending or future claims or litigation, competitive factors, technology advances, actions of regulatory agencies, and changes in laws, government regulations, labeling or product approvals or the application or interpretation thereof. Other risk factors are described herein and in the Company’s Form 10-K and other securities filings. Many of these important factors are outside STERIS’s control. No assurances can be provided as to any result or the timing of any outcome regarding matters described in this press release, the referenced conference call or otherwise with respect to any regulatory action, administrative proceedings, government investigations, litigation, warning letters, consent decree, rebate program, transition, cost reductions, business strategies, earnings or revenue trends or future financial results (including without limitation the settlement of the SYSTEM 1 class action litigation and the regulatory matters related to SYSTEM 1E or its accessories). References to products, the consent decree, the transition or rebate program, or the class action settlement, are summaries only and should not be considered the specific terms of the decree, settlement, program or product clearance or literature. Unless legally required, the Company does not undertake to update or revise any forward-looking statements even if events make clear that any projected results, express or implied, will not be realized. Other potential risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements include, without limitation, (a) the potential for increased pressure on pricing or costs that leads to erosion of profit margins, (b) the possibility that market demand will not develop for new technologies, products or applications or the Company’s rebate program, transition plan or other business initiatives will take longer, cost more or produce lower benefits than anticipated, (c) the possibility that application of or compliance with laws, court rulings, certifications, regulations, regulatory actions, including without limitation those relating to FDA warning notices or letters, government investigations, the April 20, 2010 consent decree and related transition plan and rebate program, the SYSTEM 1E device, the outcome of any pending FDA requests, inspections or submissions, or other requirements or standards may delay, limit or prevent new product introductions, affect the production and marketing of existing products or services or otherwise affect Company performance, results, prospects or value, (d) the potential of international unrest, economic downturn or effects of currencies, tax assessments, adjustments, or anticipated rates, raw material costs or availability, benefit or retirement plan costs, or other regulatory compliance costs, (e) the possibility of reduced demand, or reductions in the rate of growth in demand, for the Company’s products and services, (f) the possibility that anticipated growth, cost savings, rebate assumptions, new product acceptance, performance or approvals, including without limitation SYSTEM 1E and accessories thereto, or other results may not be achieved, or that transition, labor, competition, timing, execution, regulatory, governmental, or other issues or risks associated with our business, industry or initiatives including, without limitation, the consent decree, rebate program, and the transition from the SYSTEM 1 processing system and adjustments to related reserves, or those matters described in our Form 10-K for the year ended March 31, 2012 and other securities filings, may adversely impact company performance, results, prospects or value, (g) the possibility that anticipated financial results or benefits of recent acquisitions will not be realized or will be other than anticipated, (h) the effect of the contraction in credit availability, as well as the ability of our Customers and suppliers to adequately access the credit markets when needed, and (i) those risks described in our securities filings including our Annual Report on Form 10-K for the year ended March 31, 2012, and other securities filings.

Contact: Julie Winter, Director, Investor Relations at 440-392-7245.

STERIS Corporation

Consolidated Condensed Statements of Operations

(In thousands, except per share data)

STERIS Corporation

Consolidated Condensed Balance Sheets

(In thousands)

STERIS Corporation

Segment Data

(In thousands)

STERIS Corporation

Consolidated Condensed Statements of Cash Flows

(In thousands)

The following table presents a financial measure which is considered to be “non-GAAP financial measures” under Securities Exchange Commission rules. Free cash flow is defined by the Company as cash flows from operating activities less purchases of property, plant, equipment and intangibles, net (capital expenditures) plus proceeds from the sale of property, plant, equipment and intangibles. The Company uses free cash flow as a measure to gauge its ability to fund future principal debt repayments, growth outside of core operations, repurchase common shares, and pay cash dividends. STERIS’s calculation of free cash flow may vary from other companies.

STERIS Corporation

Non-GAAP Earnings Per Share and Outlook

The Company has referred to an adjusted financial measure regarding the results of operations excluding certain items to provide meaningful comparative analysis between the periods. This financial measure is considered to be a “non-GAAP financial measure” under Securities Exchange Commission rules. Reconciliation of the financial measure to its nearest GAAP financial measure is provided in the table below.

STERIS Corporation

Non-GAAP Financial Measures

(In thousands, except per share data)

The Company has referred to certain adjusted financial measures regarding the results of operations excluding certain items to provide meaningful comparative analysis between the periods. These financial measures are considered to be “non-GAAP financial measure” under Securities Exchange Commission rules. Reconciliation of each financial measure to its nearest GAAP financial measure is provided in the table below.

STERIS Corporation

Unaudited Supplemental Financial Data

Second Quarter Fiscal 2013

As of September 30, 2012