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About us

Allessa as a member of the Weylchem Group of Companies is one of the leading European contract manufacturers of fine chemicals with about 150 years of experience in the synthesis of organic compounds and polymers. With 550 people, we produce intermediates and active products for the agrochemical, pharma, ligand, electronics, pigments and dyes as well as speciality markets and a variety of other applications.

Allessas modern multipurpose plants allow flexible and cost-effective production and multi-step custom synthesis and contract manufacturing in a scale from pilot quantities to several hundred tons per product and year. We offer a broad variety of technologies and production capabilities for complex chemical syntheses in large scale, including advanced technologies such as low-temperature chemistry, high pressure reactions or reactions with organometallic compounds. On three sites in the Rhein-Main-area (Fechenheim, Griesheim and Hoechst) we operate six large-scale multipurpose plants and two pilot plants, as well as a large-scale hydrogenation facility. Our partner company Weylchem Frankfurt GmbH operates two more multipurpose facilities at the Griesheim site. All three sites enjoy an excellent connection to the airport, trains, rail and road transport.

Our custom manufacturing capabilities are complemented by a range of line products (aromatic amines) and performance products (phenothiazine as a stabilizer, Allessan CAP as a coupling reagent, biopolymers (Sensatis (R) and Velvetol(R)) as thickeners and solvents or acrylate polymers for various markets like cosmetics and oilfield industries.

Allessa operates according to ISO-standards 9001, 14001, 50001 and in selected plants according to cosmetic GMP standards. We adhere strict to the environmental laws, operate our own waste water treatment and commit fully to the voluntary guidelines of EFCG/CEFIC.


Allessa GmbH

Dr. Michael Hassler, Business Director
Alt-Fechenheim 34
60386 Frankfurt am Main

fon: +49 69 4109-2247
fax: +49 69 4109-2100
e-mail: michael.hassler[at]
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