Managing Director
Graduate Chemist

Phone: +49 2273 59280-285
E-Mail: matthias.bender@mbbm-cert.com

Dr. Matthias Bender has been an publically appointed and sworn expert for verifications in greenhouse gas emissions trading since 2004.

After studying chemistry and completing his doctorate on the thermodynamics of liquid mixtures at Heidelberg University (1991), Dr. Matthias Bender worked for Müller-BBM GmbH from 1992 to 2012, most recently in a managing position in the areas of environmental measurement technology, ambient air prognostics and the preparation of ambient air protection reports. Dr. Bender has been a member of the management board of Müller-BBM Cert Umweltgutachter GmbH, which was founded in the same year, since 2012 and works there as lead auditor for greenhouse gas emissions trading and lead auditor for management systems.

stefan braeker

Dr. Stefan Bräker

Managing Director
Graduated Geographer, Assessor,
Approved Environmental Verifier (DAU)

Phone: +49 2273 59280-183
Email: stefan.braeker@mbbm-cert.com

Dr. Stefan Bräker has been working in the field of corporate environmental protection since 1991. He has been a licensed environmental verifier since 2007 and an publically appointed and sworn expert for verifications in greenhouse gas emissions trading since 2004.

After his studies in geography, the 2nd state examination for higher administrative service (1991) and a doctorate at the University of Tübingen on ecosystem research (2000), Dr. Stefan Bräker has been working for the Dr. Werner Wohlfarth management consultancy for environmental protection from 1991 to 2010, most recently in the management.

Dr. Stefan Bräker invests his competence and experience also in the environmental expert committee of the Federal Environment Ministry, as deputy chairman in the working committee for greenhouse gas management of DIN NAGUS and occasionally as a speaker and lecturer on issues of corporate environmental protection for training providers. Dr. Bräker is a lead verifier in greenhouse gas emissions trading and a lead auditor for environmental, energy, quality and occupational health and safety management systems.

Gabriel von Mueller

Gabriel von Müller

M.Sc. Technical Environmental Protection

Phone: +49 2273 59280-193
E-Mail: gabriel.vonmueller@mbbm-cert.com

Mr. von Müller studied technical environmental protection in a bachelor’s and master’s degree at the TU Berlin. His focus was on environmental process technology, drinking water treatment and chemistry, and aquatic microbiology. He wrote his thesis on the topics “Abiotic Mn-Reduction in Soils Caused by Biochar – Effects on Mn Speciation and Heavy Metal Mobility” and “Development and Assessment of Methods for the Determination of BAT-AEL based on Emission Datasets of the German Chemical Industry “. Since January 2018 he is part of the team at Müller-BBM Cert Umweltgutachter GmbH as an analyst. He specializes in auditing sustainability reports and the carbon footprint.

Sandra Bender

Sandra Bender

Graduate Engineer (FH)

Telephone: +49 2273 59280-187
E-Mail: sandra.bender@mbbm-cert.com

Sandra Bender completed her studies in chemical engineering at the Aachen University of Applied Sciences, Jülich department, majoring in biotechnology, in 1998 as a Dipl.-Ing. (FH) off. She then qualified as a quality and environmental manager (DGQ). Since 1999, Sandra Bender has worked for various engineering and consulting companies. Her areas of responsibility included the preparation of safety-related analyzes and reports and the introduction of management systems. Ms. Bender works as a senior examiner in greenhouse gas emissions trading and as a senior auditor for environmental, energy and occupational safety management systems for Müller-BBM Cert Umweltgutachter GmbH.

Joerg Zens

Dr. Joerg Zens

M.Sc. Applied Geography

Phone: +49 2273 59280-192
Email: joerg.zens@mbbm-cert.com

Dr. Joerg Zens has a Bachelor’s and Master’s degree in Applied Geography at RWTH Aachen University. This was followed by a freelance activity in water protection and employment as a Ph.D. student at the Chair of Physical Geography and Geoecology (RWTH Aachen University). His dissertation dealt with the topic “The chronostratigraphy of the Last Glacial cycle recorded in loess-palaeosol sequences from Western and Central Europe”. Dr. Since August 2017, Zens is part of the team at Müller-BBM Cert Umweltgutachter GmbH. He is lead auditor in greenhouse gas emissions trading and lead auditor for energy management systems.

Emer Entrup

M.Sc. Geography

Telephone: +49 2273 59280-194
Email: emer.hartwig@mbbm-cert.com

Emer Entrup graduated from RWTH Aachen University with a bachelor’s degree in geo-resource management and subsequently completed a master’s degree in geography at Ruhr University Bochum. Her focus was on landscape ecology, climate change and climate adaptation as well as environmental problems and conflicts. In her thesis, she analysed climate data of extreme locations in Alaska and during an internship in public administration she supported projects in the field of sustainability. Since October 2021, Ms. Entrup is part of the team of Müller-BBM Cert Umweltgutachter GmbH as an analyst.

Paula Hellmich

Paula Hellmich

M.Sc. Economics

Phone: +49 2273 59280-85
Email: paula.hellmich@mbbm-cert.com

Paula Hellmich graduated from the University of Cologne with a bachelor’s and master’s degree in economics. Within her thesis, she examined the effects of economic growth on environmental pollution, as well as the long-term changes in the labor market and other economic factors due to the advancing digitization and automation of work processes. During and after her studies, she worked at the Cologne Institute for Economic Research in the field of collective bargaining policy and work relations. Since January 2019, Ms. Hellmich has been part of the team at Müller-BBM Cert Umweltgutachter GmbH as an analyst. She specializes in carbon footprints and the verification of information in non-financial statements.

Peter Hatz

Peter Hatz

Graduate Designer, M.Sc. Process Management

Phone: +49 2273 59280-129
Email: peter.hatz@mbbm-cert.com

Peter Hatz holds a diploma in product design from the Bauhaus University Weimar. After his time at the Bauhaus University, he joined the transdisciplinary master’s programme “Product Design and Process Development”, a cooperation between the Institute of Technology Cologne and the Cologne International School of Design. He wrote his thesis at the Potsdam Institute for Climate Impact Research on the subject “Sustainability Optimization of Business Processes”. Peter Hatz is working with the team at Müller-BBM Cert Umweltgutachter GmbH in the areas of process efficiency, product development and corporate communications.

Stephanie Leisten

M.Sc. Applied Geography

Phone: +49 2273 59280-182
Email: stephanie.listen@mbbm-cert.com

Ms. Leisten completed her bachelor’s and master’s degree in applied geography at RWTH Aachen University. In addition to her studies, she was employed as a research assistant in laboratory work and teached at the chair for physical geography. She wrote her thesis on the subjects of “Environmental pollution and risks from the entry of pharmaceuticals as a result of the irrigation of agricultural areas with wastewater” and “Colluvia in the Rhineland: Sedimentological and geochemical investigations based on the case study of the Köhm Rinne (Garzweiler opencast mine)”. Since January 2015, Ms. Leisten has been part of the team at Müller-BBM Cert Umweltgutachter GmbH. She is lead verifier in greenhouse gas emissions trading and lead auditor for energy management systems.

Christa Meyer

Christa Meyer


Phone: +49 2273 59280-188
Email: christa.meyer@mbbm-cert.com

After completing her training at the secretary school in Cologne, Ms. Meyer worked in various industries as a team assistant, including in bookkeeping and accounting as well as property management. Mrs. Meyer has been with the Müller-BBM Group for many years and has supported the team at Müller-BBM Umweltgutachter Cert GmbH since the company was founded.

Alexander Woywode

M.Sc. Georesource Management

Telephone: +49 2273 59280-171
Email: alexander.woywode@mbbm-cert.com

Alexander Woywode completed his bachelor’s and master’s degrees in georesource management at RWTH Aachen University. He then worked for several years as a municipal climate protection manager in city administrations. Since September 2021, Mr. Woywode is part of the team at Müller-BBM Cert Umweltgutachter GmbH.



Quino, with its real name
Sporty Springers Quickstep in Black
was born on June 21, 2017 in Lippetal and has a family tree that extends from the top of Cologne Cathedral to the crypt.

He came to Meerbusch at the age of 8 weeks. As a graduate of several puppy play and young dog training groups, he is ideally qualified for a socially compatible (office) life with two-legged friends.

Quino has been part of the Müller-BBM Cert GmbH team since mid-September 2017. Since then he has enriched the offices and the work-life of all colleagues with his engaging and friendly nature and his valued presence.

His motivation and core competence is to put a smile on people’s faces. Therefore, that is also his main area of responsibility.

Small games and brawls, the metabolism of dog treats and the upbringing of the two-legged friends round off his profile.


Aiven von den Haubergen is the youngest colleague joining the team at Müller-BBM Cert Umweltgutachter GmbH.

He is in no way inferior to his big brother in terms of efficiency in dealing with the in-house education group.

His tasks are the same as Quino’s: Keeping the company up and running.

Thanks god, they are both unbeatable at this.