October 30, 2008

Metabolix Announces That Mirel(TM) Bioplastic Resins Are Certified to European Vincotte Biodegradability for Soil and Fresh Water Standards

Metabolix, Inc. (NASDAQ: MBLX) announced that Mirel(TM) bioplastic resins produced by Telles(TM), its joint venture with Archer Daniels Midland Company, have received the European conformity certification of "OK Biodegradable Soil" for natural soil biodegradability and "OK Biodegradable Water" for fresh water biodegradability from Vincotte.

Belgium-based Vincotte is the recognized European authority on materials inspection, certification, assessments and technical training. The Vincotte label communicates a cradle to grave concept that is highly desirable for brand owners and OEMs wishing to reduce environmental impact by specifying materials that integrate biodegradability with disposal methods or infrastructure. The OK Biodegradable Soil mark verifies that certified materials will biodegrade in a natural soil environment. The OK Biodegradable Water mark verifies that certified materials will biodegrade in a natural fresh water environment such as rivers, lakes or any natural fresh water.

"These certifications validate the environmental value proposition of Mirel bioplastics in applications where end of life, intentionally or unintentionally, is in soil or marine environments," said Bob Findlen, Vice President of Sales and Marketing of Telles. "Gaining Vincotte certification for soil and water biodegradation reinforces our decision to target agricultural, horticultural and marine markets that require an end of life scenario where direct contact with a natural environment provides biodegradability. This is a significant milestone for the marketing of Mirel into these significant global markets."

Global regulations are becoming increasingly strict about the use and marketing of recyclable or biodegradable materials and products. As consumers grow more environmentally conscious, they are also becoming more aware of "green" labeling on the products they buy. Vincotte's certification is aimed at helping consumers to identify, via a labeling system, products that will biodegrade in soil and fresh water.

"Telles is the first manufacturer of high performance resins in North America to meet the qualifications necessary to be granted both the OK Biodegradable Soil and OK Biodegradable Water certificates," said Petra Michiels, Contract Manager OK Compost of Vincotte.

Mirel is the second biobased resin worldwide, starch-based being the first, to obtain both the soil and fresh water product certifications. However, unlike starch-based biopolymers, Mirel has performance properties resembling traditional, petroleum-based plastics. The OK Biodegradable Soil and OK Biodegradable Water certifications indicate to brand owners and consumers that the biomaterial has passed tests and examinations in accordance with current European standards and pertinent documentation.

About Metabolix

Founded in 1992, Metabolix, Inc. is an innovation driven bioscience company focused on providing sustainable solutions for the world's needs for plastics, chemicals and energy. The Company is taking a systems approach, from gene to end product, integrating sophisticated biotechnology with advanced industrial practice. Metabolix is now developing and commercializing Mirel(TM) bioplastics, a sustainable and biodegradable alternative to petroleum-based plastics. Mirel is suitable for injection molding, extrusion coating, cast film and sheet, blown film and thermoforming. Metabolix is also developing a proprietary platform technology for co-producing plastics, chemicals and energy, from crops such as switchgrass, oilseeds and sugarcane.

Metabolix and Archer Daniels Midland Company (ADM) are commercializing Mirel through a joint venture called Telles. The first commercial scale Mirel production plant is being constructed adjacent to ADM's wet corn mill in Clinton, Iowa. The plant is designed to produce up to 110 million pounds of Mirel annually. Mirel will reduce reliance on petroleum and decrease environmental impacts relative to conventional petroleum-based plastics.

For more information, please visit www.metabolix.com.

Safe Harbor for Forward-Looking Statements

This press release contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements in this release do not constitute guarantees of future performance. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements regarding commercial viability of Mirel, and expectations regarding Mirel commercial production and the commercially produced Mirel material, constitute forward-looking statements. Such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated, including, without limitation, risks associated with: the Company's ability to develop and successfully commercialize Mirel, market acceptance of Metabolix products, the Company's ability to compete with petroleum-based plastics, chemicals and energy and with other biobased products, and other risks detailed in Metabolix's filings with the Securities and Exchange Commission, including form 10-K for the year ended December 31, 2007, which was filed on March 13, 2008, and form 10-Q for the quarter ended March 31, 2008, which was filed on May 8, 2008. Metabolix assumes no obligation to update any forward-looking information contained in this press release or with respect to the announcements described herein.