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Washington, DC
Greg Clark
©2024 Keller and Heckman LLP

Greg Clark counsels clients on regulatory and environmental issues, focusing on the Toxic Substances Control Act (TSCA), the Clean Air Act (CAA), state volatile organic compound (VOC) regulations, the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the Clean Water Act (CWA), and the Resource Conservation and Recovery Act (RCRA).

Greg assists clients needing approval of new chemical substances, genetically modified organisms (GMOs), and pesticides under TSCA, FIFRA, and similar laws abroad. Clients value his extensive experience guiding them through the Premanufacture Notification (PMN), Low Volume Exemption, Microbial Commercial Activity Notice (MCAN), and TSCA Environmental Release Application (TERA) review processes. He also assists clients by negotiating the terms and conditions of TSCA Section 5(e) consent orders and Significant New Use Rules (SNURs). Additionally, Greg advises companies seeking to market biotechnology-derived products and their production platforms (including bacteria, yeast, algae, and plants) while navigating the complex regulatory requirements administered by the U.S. Environmental Protection Agency (EPA), the U.S. Food and Drug Administration (FDA), and the Animal and Plant Health Inspection Service (APHIS).  

Greg’s extensive background enables him to provide guidance to companies and trade associations on the prioritization, risk evaluation, and risk management of existing chemicals, including chemicals on the 2014 TSCA Work Plan, following the Lautenberg Act amendments to TSCA. Through this work, he develops detailed comments and regularly interacts with EPA staff. He assists companies with periodic reporting under the TSCA Chemical Data Reporting Rule and other agency reporting programs. He also designs, conducts, and coordinates comprehensive internal audits of TSCA compliance for existing operations under EPA’s “Audit Policy,” as well as under other penalty mitigation policies.

Greg has in-depth knowledge representing clients in CAA rulemakings and enforcement matters before administrative agencies, including drafting highly technical comments, filing petitions for reconsideration and judicial review, and meeting with agency staff. 

Greg has a background in molecular biology and emergency preparedness, offering him a unique foundation from which to advise his clients and assist the firm.

Representative Matters

  • Organized and conducted a voluntary TSCA compliance audit of a specialty chemicals company covering hundreds of products and multiple sites, resulting in elimination of significant civil monetary penalties
  • Represented a trade association before the U.S. EPA and the U.S. Court of Appeals for the District of Columbia Circuit in a challenge to a CAA regulation
  • Represented a specialty chemicals company in obtaining chemical inventory corrections for a key product in the U.S., Canada, and Australia
  • Represented a commercial and consumer products company in $10 million enforcement proceedings initiated by a California air district concerning VOC regulations for consumer products


  • American Bar Association (ABA), Pesticide, Chemical Regulation, and Right-to-Know Committee


  • The Best Lawyers in America®: Ones to Watch: Environmental Law, 2024


James Madison University, B.S., 2005 magna cum laude
University of Virginia, J.D., 2010