Paul Parsons
Paul Parsons, Ph.D.
Senior Managing Scientist
Chemical Regulation & Food Safety
Harrogate (UK)

Dr. Parsons is a highly experienced regulatory toxicologist with an in-depth knowledge of pesticides and chemicals regulation globally gained during his 19 years working for a major crop protection company and 5 years working for UK regulatory authorities. In various roles in regulatory toxicology and human health science Dr. Parsons has worked across the full product lifecycle including defense of existing products in the market place, leadership of a team of up to 30 scientists focused on research to identify, optimize and select candidates for development and project leader for several new active ingredient development programs. Dr. Parsons has led or had major involvement in the development of the full regulatory toxicology database for at least 15 new active ingredients that have been successfully commercialized illustrating his considerable experience in the design, conduct and interpretation of the full breadth of regulatory and investigative toxicity studies for the active ingredient, metabolites, manufacturing intermediates, impurities and formulated products. Although Dr. Parsons has worked across all pesticides indications including insecticides, herbicides and crop enhancement, he has extensive expertise in fungicides, particularly in research and development of new fungicide active ingredients.

In addition to data generation, Dr. Parsons has in-depth experience in the downstream use of toxicity data in human health risk assessment and hazard classification in all key regulatory regions of the World. A key strength is his ability to integrate mammalian toxicity data across the holistic product profile for end-points such as residue definition, groundwater metabolite relevance, technical AI equivalence and endocrine disruption implications for humans and wildlife. In resolving complex techno-regulatory problems that frequently arise in these areas, Dr. Parsons maintains a focus on addressing the key scientific questions that can affect downstream regulatory decision making and risk management.

Dr. Parsons experience as a regulatory toxicologist is truly global. Having developed the data and techno-regulatory positioning for multiple submission dossiers for many molecules, Dr. Parsons has had significant involvement in pre- and post-submission discussions with regulatory authorities in all key regions of the World including Europe, North America, Latin America (mainly Brazil), China and Japan. From 2002-2005, Dr. Parsons lived and worked in Greensboro, North Carolina and gained a detailed understanding of US EPA’s regulatory requirements and science policies. During this time Dr. Parsons was a member of industry task forces including the US Triazoles Task Force (USTTF) which adDr.essed US EPA’s data needs and human health risk assessment for the common triazole metabolites and the Pyrethroids Working Group, which focused on developing novel scientific approaches for defining Common Assessment Groups for the pyrethroids as a pre-requisite for cumulative risk assessment. On returning to the UK Dr. Parsons continued to work on the common triazole metabolites through the Triazole Derivative Metabolite Group (TDMG). 

In recent years, Dr. Parsons led a team of scientists focused on investigating carcinogenic modes of action for several related molecules with the specific aim of demonstrating modes of action and adverse outcome pathways in the animal model and making a judgment on their relevance to humans. This included well-described modes of action such as rodent liver and thyroid in addition to more novel modes of action requiring bespoke investigative toxicity studies to elucidate the key events and establish novel adverse outcome pathways. The design and downstream positioning of these investigative programs was guided by Dr. Parsons in-depth experience of cancer hazard classification and risk assessment in Europe and North America. This enabled informed regulatory decisions to be made on the need for non-linear versus linear extrapolation approaches to cancer risk assessment and assignment of appropriate cancer hazard classification based on an evidence-based assessment of human relevance. 

Dr. Parsons is a strong advocate for making the best use of the rapidly developing science that underpins the various disciplines within toxicology especially in early-stage research which is less constrained by the requirements of regulatory toxicity testing. He has significant experience of evaluating the potential for selectivity against the pesticidal target using in vitro systems that allow inter-species comparison of potency against key biological targets and the potential for systemic exposure which in combination allows prediction of potential in vivo toxicological outcomes. Dr. Parsons has been involved with several projects working with regulatory agencies to explore opportunities to employ state of the art scientific approaches within a risk-based testing paradigm to compliment or modify the standard in vivo regulatory toxicology package that is currently required for global registration. 

For over 10 years, Dr. Parsons has been involved in the design and delivery of training events intended to enhance the key behavioral and communication skills required for successful advocacy. The knowledge and experience from these courses underpins Dr. Parsons’ strength in the developing options for the techno-regulatory positioning of challenging toxicological and human health issues.

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Toxicology & Pharmacology, University of Manchester, UK, 1994
  • M.Sc., Toxicology, University of Birmingham, UK, 1991
  • Fellowship of the Institute of Biomedical Sciences, Liverpool John Moores University, 1990

Publications

Parsons, P.P., Garland, H.O. and Harpur, E.S. (1993) Journal of Physiology 473, 272p. Acute effects of gentamicin on urinary NAG and calcium excretion in the anaesthetized rat.

Parsons, P.P., Garland, H.O. and Harpur, E.S. (1994) Human and Experimental Toxicology. 13 (4); 284. Assessment of the dose-response relationship and nephron site of gentamicin-induced hypercalciuria in the anaesthetised rat.

Parsons, P.P., Garland, H.O. and Harpur, E.S. (1995) Kidney International 47; 667. An investigation of the nephron site of gentamicin-induced hypercalciuria in the anaesthetised rat.

Parsons, P.P., Garland, H.O. and Harpur, E.S. (1995) Journal of Physiology 483; 168P. Effect of gentamicin on urinary recoveries of 45Ca from distal tubular microperfusions in the anaesthetised rat.

Parsons, P.P. Garland, H.O., Harpur, E.S. and Old, S. (1997) British Journal of Pharmacology 122, 570-576. Acute gentamicin-induced hypercalciuria and hypermagnesiuria in the rat: dose-response relationship and role of renal tubular injury.

Indans, I. Fry, T. Parsons, P.P. et al. (1998) Human and Experimental Toxicology 17; 98. Classification and labelling of industrial chemicals for acute toxicity, skin and eye irritation.

Tichias, K., Fentem, J. Parsons, P.P. et al. (1998) Alternatives to Laboratory Animals 26; 619-627. Progress in toxicological testing: reduction and refinement issues.

Anderson, D., Elovaa, E., Frantik, E., Parsons, P.P. et al. (1999) International Programme on Chemical Safety. (1999) Environmental Health Criteria 208 Carbon Tetrachloride. World Health Organisation. 

Parsons, P.P., Garland, H.O. and Harpur, E.S. (2000) British Journal of Pharmacology 130; 441-449. Localization of the nephron site of gentamicin-induced hypercalciuria in the rat: a micropuncture study.

Parsons, P.P. (2001) Mammalian Toxicokinetics and Toxicity of Chlorothalonil. In: Handbook of Pesticide Toxicology (Second Edition) Ed. R. Krieger, Academic Press, pp 1743-1757. 

Atreya, N.C., Turner, C and Parsons P.P. (2002) Gaining Consumer Confidence (Residues of Crop Protection Products in Food). Published by Syngenta Crop Protection, Whittlesford, UK. 

Currie, R.A., Green, R.M., Wright, J.A. & Parsons, P.P. (2012) Mode-of-Action and Lack of Human Health Relevance of Increased Hepatocellular Adenoma in the Female Han Wistar Rat Treated with Isopyrazam. In: The Toxicologist: Supplement to Toxicological Sciences, [126 (1)], Society of Toxicology, [2012]. Abstract no. 2681.

Parsons, P.P. (2012) Safety Evaluation of New Pesticide Active Ingredients: Enquiry-Led Approach to Data Generation. Modern Methods in Crop Protection Research (Second Edition), Eds Jeschke P, Krämer W, Schirmer, U & Witschel M. Wiley-VCH, pp 351-379.

Moore, N.P., Boogaard, P.J., Bremer, S., Parsons, P.P et al. (2013) Guidance on Classification for Reproductive Toxicity Under Globally Harmonized Classification and Labelling of Chemicals (GHS). Critical Reviews in Toxicology 43(10); 850-891.

Green, R.M., Parsons P.P., Peffer R.C., Wright, J.A., Currie, R.A. (2014) Mode of Action and Lack of Human Relevance of Benzovindiflupyr (SolatenolTM)-Induced Thyroid Follicular Cell Adenoma in Male Han Wistar Rats. In: The Toxicologist: Supplement to Toxicological Sciences, [138 (1)], Society of Toxicology, [2014]. Abstract no. 238.

Prior Experience

Principal Regulatory Toxicologist, Syngenta Crop Protection Limited, 1998-2018

Senior Scientific Officer, UK Health & Safety Executive, Pesticides Registration Section, 1994-1998

Medical Laboratory Scientific Officer (Clinical Biochemistry), National Health Service, UK, 1985-1990

Professional Affiliations

British Toxicology Society, member

Project Experience

Lead toxicologist for the design, conduct, interpretation and positioning (pre-and post-submission) of the mammalian toxicity data base for several new active substances

Extensive experience in crop protection research projects for fungicides, herbicides, insecticides and crop enhancement from early stage chemistry to selection of candidates for full development

Lead role in the design, conduct and interpretation of bespoke investigative toxicity studies to establish novel neuroendocrine mode of action to adDr.ess cancer classification and human health risk assessment

Development of successful study waivers for carcinogenicity and other long-term toxicity tests requested for manufacturing intermediates and metabolites under NONS/REACH, China’s Order No. 7 and 40 CFR Part 158.

ILSI HESI Risk Assessment in the 21st Century Project

UK All Party Parliamentary Working Group Chemical Regulation in the EU

ECETOC Working Group on Classification for Reproductive Toxicity under GHS

Design and delivery of workshop to share perspectives with Chinese regulatory agencies (including ICAMA, MEP, CDC, CFSA) on approaches for elucidating carcinogenic modes of action, weight of evidence evaluation, cancer hazard classification in the EU and USA and exposure-based approaches to human health risk assessment in the 21st Century

News & Events

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Toxicology & Pharmacology, University of Manchester, UK, 1994
  • M.Sc., Toxicology, University of Birmingham, UK, 1991
  • Fellowship of the Institute of Biomedical Sciences, Liverpool John Moores University, 1990