Benefit from our experience
The Team
Linge Agroconsultancy, founded on 1 February 2003, is an independent consulting company specialised in the authorisation of plant protection products, biocides and the approval of active substances in Europe.
Our experienced registration experts are at your side to guide and assist you at every stage of registration of your active substances or products.
dr. A.J.G. Engels (Tonnie)
Managing director
Tonnie Engels has been director of Linge Agroconsultancy since it was founded in 2003. He is an engineer in Plant Cultivation and holds a PhD in Agricultural Sciences and Plant Pathology. Tonnie has gained fundamental and practical research experience during his previous and current activities. He has extensive experience in the registration of plant protection products, active substances and biocides. He coordinated and managed registration projects for many of these products. In addition, he was seconded as a scientific assessor of efficacy and as a temporary project leader at the Board for the Authorization of Plant Protection Products and Biocides (Ctgb) in the Netherlands. In addition, he was seconded as a Registration Specialist at various companies in the crop protection industry. Tonnie speaks Dutch as his mother tongue, is fluent in English and has a working knowledge of German.
S. van Aken MSc (Sef)
Registration specialist
Sef van Aken is a consultant and expert with over 10 years of professional experience in regulatory affairs and consultancy. He holds an MSc in Biology. He is experienced in modelling, risk analyses, evaluation of Human Toxicology, Environmental Fate and Ecotoxicology studies, dossier preparations and post-submission activities on national and European level. He carried out evaluations as a scientific assessor Ecotoxicology for the Board for the Authorisation of Plant Protection Products and Biocides (Ctgb) in the Netherlands. He carried out many projects on registration and approval of plant protection products and substances (also low risk) for both government and trade and industry.
He is a certified ToxRat specialist with extensive experience in evaluation of OECD and non-OECD ecotox studies and statistical assessments.
Prior to working at Linge Agroconsultancy, he was research employee at a Dutch research organisation specialised in crop protection in agriculture and horticulture. Sef speaks Dutch as mother tongue and is fluent in English.
ir. K. Apenhorst (Karen)
Registration specialist
Karen Apenhorst has been working professionally in regulation and consultancy since 2012. She is an engineer in Biology, specialized in plant biology. Her main expertise is efficacy of plant protection products at national and European level. In addition, she has expertise in comparative assessment, literature studies and practical knowledge of risk analyses, environment and ecotoxicology, dossier preparation and post-submission activities at national and European level. She carries out evaluations as a scientific assessor of efficacy for the Board for the Authorization of Plant Protection Products and Biocides (Ctgb) in the Netherlands. She has carried out several registration projects for products and active substances (including low risk), and is an expert in writing biological dossiers (BAD) and dRR efficacy for both government and industry. Karen speaks Dutch as her mother tongue, is fluent in English and has a working knowledge of German.
ir. P.W.M. de Boer (Paul)
Registration specialist
Paul de Boer is a senior consultant and expert with professional experience in regulatory affairs and consultancy since 2008. He holds an MSc in Plant Breeding and Crop Protection. His main expertise is Efficacy on national and European level on both plant protection products and biocides. He had a secondment at Dutch Competent Authority as a biocide efficacy expert in 2018/2019. He is an expert in writing and evaluating biological records (BAD) and dRR efficacy and advises industry on designing and conducting efficacy studies. He is experienced in training foreign governmental organizations in Africa. Prior to working at Linge Agroconsultancy, he worked as a plant breeder and as an advisor and researcher in the crop protection area. Paul speaks Dutch as mother tongue and is fluent in English and has working knowledge of Spanish.
ir. L. Feher (Lisette)
Registration specialist
Lisette Fehér has professional experience in regulatory affairs and consultancy since 2017. She holds an MSc in Crop Sciences. She carries out projects on registration and approval of plant protection products for both government and trade and industry. She has knowledge on environmental modelling, risk analyses, evaluation of Ecotoxicology and Environmental Fate studies, dossier preparations and post-submission activities on national and European level. Lisette speaks Dutch as mother tongue and is fluent in English.
dr. R.W. Kolnaar (Rogier)
Registration manager
Rogier Kolnaar is a senior consultant and expert in regulatory affairs since 2001 and has consulting experience since 2006. He holds an MSc in Crop Protection and PhD in Agricultural Sciences. Rogier coordinated regulatory projects of chemical and microbial plant protection products and their active substances (including low risk) for more than 30 companies. He is experienced in regulatory procedures, Phys-Chem properties, Classification, risk analyses, MRLs, Ecotoxicology, dossier preparations and post-submission activities on national and European level. He has been seconded at the Board for the Authorisation of Plant Protection Products and Biocides (Ctgb) in the Netherlands as evaluator plant protection products for aspects Ecotoxicology and Residues and has been seconded as temporary project leader of plant protection products and biocides. Prior to working at Linge Agroconsultancy, he was registration officer for 5 years at a Dutch company that develops and produces biological control products. Rogier speaks Dutch as mother tongue, is fluent in English, proficient in German and has working knowledge of French and Spanish.
dr. J. Krook (Janhendrik)
Registration specialist
Janhendrik Krook has been graduated as MSc in biology and holds a PhD in Plant Physiology/Biochemistry. He has professional experience as a risk assessor at the Board for the Authorisation of Plant Protection Products and Biocides (Ctgb) in the Netherlands, where he was involved in Residue / MRL evaluations, and Consumer health risk assessment (EU active substance peer review program), 2000-2012. He has experience in biocide registration procedures at Linge Agroconsultancy from 2012 and was acting in secondment in registration activities at plant protection industries and in training of foreign governmental organizations in Europe, Africa and Asia. He is seconded at the Board for the Authorisation of Plant Protection Products and Biocides (Ctgb) in the Netherlands as evaluator Residues of plant protection products and active substances. Janhendrik speaks Dutch as mother tongue, is fluent in English and has working knowledge of German and French.
A.C.M. Reulink-Hermsen MSc (Annicka)
Registration specialist
Annicka Reulink has been working at Linge Agroconsultancy since 2016. She holds an MSc in Environmental Sciences (specialisation: Human and Environmental risk assessment). She performs evaluations as a scientific assessor Ecotoxicology for the Board for the Authorisation of Plant Protection Products and Biocides (Ctgb) in the Netherlands. She carries out projects on registration and approval of plant protection products and active substances for both government and trade and industry. She has knowledge on environmental modelling, risk analyses, evaluation of Ecotoxicology and Environmental Fate studies, Phys-Chem properties, Residues, dossier preparations and post-submission activities on national and European level. She is a certified ToxRat specialist with extensive experience in evaluation of OECD and non-OECD ecotox studies and statistical assessments. Annicka speaks Dutch as mother tongue and is fluent in English.
M. Roher MSc (Monika)
Registration specialist
Monika Roher graduated with magna cum laude MSc in Phytomedicine at Faculty of Agriculture University of Zagreb. She is experienced in molecular mechanisms of plant disease control and in scientific literature evaluations. She has experience in scientific research since 2016. She is working at Linge Agroconsultancy from January 2020 and is involved in active substance renewal projects as well as in projects on registration and approval of plant protection products. She has knowledge on environmental modelling, risk analyses, dossier preparations and post-submission activities. She is a certified ToxRat specialist with experience in evaluation of OECD and non-OECD ecotox studies and statistical assessments.
As a part of her master’s thesis she did research on the effects of plant extracts on plant and thrips at University of Natural Resources and Life Sciences Vienna. As an intern, she was involved in research on biological control of Western flower thrips at Wageningen University and Research. Monika speaks Croatian as mother tongue and is fluent in English.
B. Spruit MSc (Ben)
Registration specialist
Ben Spruit has been graduated as MSc in biology at Leiden University. He spent some years working in education before moving to the crop protection industry in 2016, where he gained professional experience in regulatory affairs of (organic) plant protection products. In 2023, Ben joined Linge Agroconsultancy as registration specialist. Besides Dutch as his mother tongue, he speaks English and Italian.
Ir. I. Zwartjes (Ilse)
Registration specialist
Ilse Zwartjes Ilse has several years of experience in registration of plant protection products and consultancy. Besides that she has worked on other regulatory subjects, for example on chemicals used in the production of paint and modelling material for children. Before starting in the field of regulatory affairs she worked at a laboratory for analytical chemistry.
She holds an MSc Degree in Molecular Sciences. Ilse speaks Dutch as mother tongue, is fluent in English and has working knowledge of German and French.
Besides her work in consultancy and regulatory affairs, she is interested in the medicinal use of plants.
Eleni Kazantzidou (MSc)
Registration Specialist
Eleni Kazantzidou is a registration specialist at Linge Agroconsultancy since April 2024. She obtained her MSc degree in Environmental Science from Wageningen University & Research, with a specialization in Aquatic Ecology & Water Quality Management. Her MSc thesis and internship included field work in Kralingse Plas lake, modelling, scientific publications review and report writing. Since then, she has gained professional experience working as a scientific project manager. She was involved in the design and the progress of Good Laboratory Practice (GLP & non-GLP) compliant Ecotoxicological studies required for preclinical regulatory submissions for human pharmaceuticals, veterinary products and plant protection products. She has extensive experience in scientific report writing and in assessing biological and analytical results. Also, she is competent in performing statistical analysis with ToxRat. Besides Greek as her mother tongue, Eleni speaks English at a professional level.