John Parker Sweeney

Martindale-Hubbell® AV Preeminent Rated Association of Defense Trial Attorneys Federation of Defense and Corporate Counsel International Association of Defense Counsel Litigation Counsel of America, Fellow DRI Lifetime Professional Service Award, 2022 Listed in The Best Lawyers in America® Mass Tort Litigation & Product Liability Litigation, 2011-2012 Mass Tort Litigation/Class Actions – Defendants, 2015-2025 Product Liability Litigation – Defendants, 2013-2025 "Lawyer of the Year," Mass Tort Litigation/Class Actions – Defendants, 2021 Listed in Benchmark Litigation "Local Litigation Star," Washington, D.C., 2015-2021 "Litigation Star", 2023-2024 Listed in Maryland Super Lawyers Class Action/Mass Torts, 2007-2012 Listed in Washington, D.C. Super Lawyers, Class Action/Mass Torts, 2013-2020 Capital Pro Bono Honor Roll, 2019-2023 Representing chemical company in “popcorn worker lung” claim resulting in judgment well below final settlement offer against prominent and successful national plaintiffs counsel. Circuit Court for Baltimore County Maryland April-May 2011. Obtained numerous reported appellate decisions in federal and state appellate courts including the leading opinion on the standard for punitive damages in product liability cases in Maryland, Owens-Illinois v. Zenobia, 1992. Amicus brief in US Supreme Court for DRI in AEP v. Connecticut, 2011, supporting successful petitioners in reversing Second Circuit ruling allowing states to pursue limits on greenhouse gas emissions by utility companies. Amicus brief in US Supreme Court defending Second Amendment rights of individuals in McDonald v. City of Chicago, 2010, on behalf of 900 state lawmakers successfully supporting extension of Heller v. D.C. to the states through the Fourteenth Amendment. Amicus brief in Maryland’s highest court for the National Multi Housing Council, the national Home Builders Association, and Maryland Defense Counsel in Montgomery Mutual v. Chesson, 2007, establishing that the “generally accepted” standard of U.S. v. Frye applied in Maryland civil cases to limit expert opinion and requiring trial judges to hold Frye hearings on request, 2007. Counseled one of the country’s leading producers of educational demonstrative products for children on compliance with the Consumer Product Safety Improvement Act of 2008 and the CPSC’s regulations thereunder, including negotiating a voluntary product recall, as well as preparing written rulemaking comments and meeting with Commissioners regarding pending rulemaking proceedings. He is a leading counselor offering advice to companies on experience under the CPSC’s public product safety database. Defends clients in class action lawsuits and mass consolidations alleging indoor environmental and groundwater contamination, blood-borne diseases, injury due to excessive noise and vibration, and exposure to various toxic substances. He defends class action lawsuits in multiple jurisdictions alleging unfair or deceptive trade practices, consumer fraud, misrepresentation and breach of warranty in connection with product packaging and sales practices. Retained by one of the country’s leading home appliance manufacturers to defend a federal class action on behalf of a national class of residential boiler owners alleging implied and express warranty, misrepresentation and state consumer protection act claims, John’s motion to dismiss led to plaintiffs’ counsel amending their complaint to drop the national class in favor of a handful of individual state classes. When engaged to defend Maryland’s largest affordable housing owner/manager after the court had already certified a class action against it on illegal rent practices allegations, he successfully asserted set-off claims on any rent owed against any damages recovered that led to a quick and manageable settlement of thousands of claims. In a “sick building” case brought by Delaware financial services workers against their landlord and property manager, John obtained dismissal of the class allegations and barred plaintiffs’ experts from asserting claims of multiple chemical sensitivity, “sick building syndrome,” chronic fatigue syndrome, fibromyalgia and the like. This led to a settlement of the few individual claims and discouraged the filing of hundreds more claims. Extensive practice defending manufacturers and other corporate clients from product and premises liability claims alleging illness from occupational exposure to asbestos, hazardous chemicals and other allegedly toxic substances or harmful conditions. Sales and Rental of Manufacturer’s Construction Machinery - After obtaining dismissal of an international construction machinery manufacturer from the wrongful death action on behalf of a deceased forklift operator overcome by carbon monoxide, John was retained to respond to claims and legal disputes involving sales and rental of the manufacturer’s construction machinery around the country. Defended Real Estate Companies, Pharmaceutical and Other Consumer Product Manufacturers in Premises Liability Asbestos Cases - Successfully defended real estate companies, as well as pharmaceutical and other consumer product manufacturers in premises liability asbestos cases prosecuted in Delaware under its liberal venue provisions and preferential trial settings for plaintiffs with terminal cancer dianoses. Successful Defense of the Safety of Asbestos and Silica - A leading manufacturer of glass plant equipment received hundreds of asbestos and silica claims by East Texas glass plant workers. John’s successful defense of the safety of these products produced a dismissal without payment and helped avoid his client’s involvement in other asbestos and silica claims arising in glass plants around the country. Demonstration That Client’s Equipment Had Not Contributed to Hearing Loss or Vibration Injury - A leading industrial equipment manufacturer faced thousands of hearing loss and hand/arm vibration claims of Mississippi shipyard workers. John’s successful demonstration that his client’s equipment had not contributed to any hearing loss or vibration injury in shipyard workers resulted in dismissals with prejudice and discouraged other workers from pursuing hearing loss and hand/arm vibration claims in other shipyard and occupational settings. Obtained a Mediated Resolution of Over 12,000 Pending Claims - An international building materials manufacturer became one of 12 target defendants in the common issues trial of more than 9,000 consolidated Maryland asbestos cases. After a six-month trial in Baltimore City Circuit Court, John ultimately obtained a mediated resolution of over 12,000 pending claims that allowed his client to process claims administratively and avoid trials for years. Demonstrated Client’s Products Were Not a Cause of the Plaintiffs’ Alleged Injuries - A manufacturer of industrial lubricants was sued in hundreds of cases alleging exposure to nickel in a Texas Army Depot and dozens of cases alleging exposure to benzene in Pennsylvania steel mills. In both instances, John was able to demonstrate that his client’s products were not a cause of the many plaintiffs’ alleged injuries. Defended a Petroleum Terminal Owner and Operator Against MDE’s Claims - Facing a Maryland Department of Environment civil penalty action demanding tens of millions of dollars in civil penalties as well as injunctive relief after cooperating fully to contain and retrieve over 50,000 gallons of fuel oil in Baltimore’s Curtis Bay area, a petroleum terminal owner and operator is being defended by John against MDE’s claims. Defended Industrial Property Owner Against Amtrak’s Claims for Injunction Relief and Civil Damages - An industrial property owner was defended by John against Amtrak’s claims for injunction relief and civil damages where Amtrak alleges that run-off of storm water diverted through our client’s Maryland property has undermined Amtrak’s railbed and threatened the safety of its Northeast Corridor passenger and freight service. Defended Claims Alleging Personal Injuries and Property Value Diminution from Alleged PCBs and TCE in Groundwater - When client was sued by hundreds of New York families alleging personal injuries and property value diminution from alleged PCBs and TCE in groundwater, John defended claims and ultimately enforced an indemnification from the prior owner of the manufacturing facility, which our client had acquired subject to an indemnification agreement. Defended a client against CERCLA liability for a corporate predecessor’s alleged industrial release of perchlorate into groundwater now drawn upon by California residential communities for drinking water. By developing the groundwater and soil testing data, he was able to demonstrate that the predecessor’s activities had not contributed to contamination of the groundwater. Montgomery Mutual v. Josephine Chesson, et al., 399 Md. 314, 923 A.2d 939 - Remanding for a Frye hearing on admissibility of expert testimony diagnosing building occupants with “Sick Building Syndrome” and biotoxinassociated illness.