Controversies and Criticisms
Defective Drywall Issues
In the mid-2000s, following Hurricane Katrina's disruption of U.S. drywall supplies, Knauf Plasterboard (Tianjin) Co. Ltd., a Chinese subsidiary of German-based Knauf Gips KG, exported approximately 55 million pounds of gypsum board to the United States starting in January 2006.[63] This material, produced primarily in 2005 and 2006, contained gypsum sourced from high-sulfur mines in China's Shandong region, leading to elevated emissions of hydrogen sulfide and other sulfide gases—up to 100 times higher than in non-Chinese drywall samples.[64] [65]
The defective drywall caused widespread property damage through corrosive off-gassing, accelerating the degradation of metal components such as electrical wiring, air conditioning evaporator coils, plumbing fixtures, and appliances like refrigerators and microwaves.[66] Homeowners in affected regions, primarily the southeastern U.S. states of Florida, Louisiana, and Virginia, reported sulfurous odors and blackening of copper elements, with installations spanning thousands of residences built or renovated between 2005 and 2008.[63] Health complaints included respiratory irritation, chronic coughing, eye and throat discomfort, and headaches, though federal investigations like those by the CDC emphasized potential irritant effects without establishing definitive long-term causal links beyond corrosion-related risks.[67]
Internal communications revealed early awareness within Knauf entities; for instance, a November 2006 email from the Tianjin general manager warned German executives of potential widespread issues, while Knauf Gips KG provided technical oversight, including R&D visits to affected U.S. homes and adherence to German quality standards.[63] Knauf Gips maintained that the Tianjin subsidiary operated as a legally independent entity, denying direct liability despite 100% ownership acquired in 1999 and shared management structures, a position contrasted by a European Court of Justice ruling treating parent-subsidiary units as a single economic entity.[63]
Legal actions culminated in multiple settlements; in October 2010, Knauf Tianjin agreed to remediate 300 homes as the first major resolution, covering full replacement of affected systems.[68] A broader December 2011 agreement with Knauf entities, valued at $800 million to $1 billion, addressed remediation for up to 5,000 properties, personal injury claims, and property devaluation across multidistrict litigation in U.S. federal courts.[69] [70] Knauf executives, including board member Jörg Schanow, contested claims of inherent health risks from the product, attributing lawsuits to the company's financial resources rather than proven defects.[63] Later Knauf facilities in China, such as those in Guangdong and Wuhu, produced drywall with negligible emissions, indicating the issue was localized to the Tianjin plant's material sourcing.[64]
Business Activities in Russia
Knauf established manufacturing operations in Russia in the early 2000s, including gypsum board production facilities that contributed to the company's global expansion into Eastern European markets. By 2022, these operations represented a significant portion of Knauf's Eastern European footprint, with plants producing drywall, insulation, and related building materials for the domestic Russian construction sector.
Following Russia's invasion of Ukraine in February 2022, Knauf initially stated it had no plans to exit the Russian market, with management board member Jörg Schanow affirming the company's commitment to continued operations amid the geopolitical crisis. This stance drew criticism from outlets tracking corporate involvement in Russia, such as LeaveRussia.org, which accused Knauf of conducting business as usual and indirectly supporting the Russian economy during wartime. Knauf maintained that its activities complied with international law and did not involve military-related supply chains.[71][72]
A major controversy emerged in early 2024 when investigations revealed Knauf materials were used in the reconstruction of Mariupol, a Ukrainian city occupied by Russian forces following its 2022 siege and destruction. Reports highlighted Knauf gypsum products in projects tied to Russian state efforts to rebuild infrastructure in annexed territories, prompting accusations of complicity in legitimizing occupation. In response, German prosecutors initiated probes into Knauf's role, leading the company to announce on April 22, 2024, its decision to withdraw from Russia by transferring operations to local management and severing direct control. Knauf denied direct involvement in occupied territory projects, attributing material use to independent Russian distributors.[73][74][75]
Further scrutiny arose in May 2025 over alleged supplies of Knauf products to Russian nuclear facilities, with media reports claiming indirect support for military infrastructure, including potential nuclear weapons bases. Knauf rejected these accusations as unfounded, emphasizing that its Russian subsidiary operates organizationally separate from the parent company, with no technology transfers, imports from the EU, or exports to the EU since sanctions were imposed, in full adherence to EU and German regulations. Critics, including Ukrainian outlets like Euromaidan Press, argued that ongoing production under Knauf ownership effectively sustains Russia's war economy, regardless of profit repatriation claims.[76][77]
As of October 7, 2025, Knauf disclosed that negotiations to sell its Russian business—ongoing since April 2024—had collapsed after a potential buyer withdrew, citing an inability to finalize terms under the "very challenging environment" of sanctions and market conditions. The Russian operations, encompassing multiple factories, continue under local management with no financial flows to the German parent, though Knauf reiterated its intent to pursue further divestment options while ensuring sanctions compliance. This prolonged presence has fueled ongoing debates about the efficacy of corporate exits from Russia, with some analysts noting that "de-risking" structures like local management allow indirect continuity without full withdrawal.[78][79][80]
Labor and Other Legal Disputes
In 2022, Knauf faced a major labor dispute at its Port Melbourne, Australia, plasterboard manufacturing facility, involving approximately 70 workers affiliated with the Construction, Forestry, Maritime, Mining and Energy Union (CFMEU). The conflict arose after employees unanimously rejected an enterprise bargaining agreement proposing a 5% pay increase over three years, citing inadequate wages amid inflation, safety concerns, and excessive use of casual labor; workers commenced protected industrial action, including rolling stoppages and work bans, on August 24.[81][82] Knauf responded by locking out the workforce on September 15, prompting an indefinite strike and a 40-day picket line that disrupted production.[83][84] The standoff ended favorably for employees on October 25, with a new agreement delivering higher wage increases, enhanced safety protocols, limits on casual hires, and pathways to permanency for some workers.[85][86]
In the United States, Knauf Insulation subsidiaries have encountered employment lawsuits alleging discrimination, leave interference, and wage violations. In Sung v. Knauf Fiber Glass (S.D. Ind., judgment entered circa 2004), an employee of Korean national origin claimed race-based suspension and termination under 42 U.S.C. § 1981 after arriving to work under the influence of alcohol, which Knauf deemed a terminable offense; the court granted summary judgment for Knauf, ruling that the plaintiff failed to demonstrate pretext or discriminatory intent beyond his protected status.[87] Similarly, Aubuchon v. Knauf Fiberglass (S.D. Ind. 2003, aff'd 359 F.3d 950, 7th Cir. 2004) involved Family and Medical Leave Act claims, where the plaintiff argued Knauf's strict absenteeism policy improperly denied unforeseeable leave for a serious health condition; courts upheld Knauf's position, finding inadequate notice under the statute and consistent policy enforcement against excessive absences.[88][89]
Additional U.S. labor actions include Richard Brancaccio v. Knauf Insulation (C.D. Cal., filed 2020), asserting nine causes of action under California labor codes for alleged wage, hour, and rest break violations, which was remanded to state court for further proceedings.[90] A more recent filing, Guerra v. Knauf Insulation (E.D. Cal., filed October 2024), pertains to unspecified labor standards under federal oversight.[91] In 2019, the National Labor Relations Board docketed an unfair labor practice charge from the Glass, Molders, Pottery, Plastics & Allied Workers Local 32 against Knauf Insulation in Shelbyville, Indiana (Case 25-CB-235057), though resolution details remain non-public.[92]
Beyond labor matters, Knauf has litigated intellectual property disputes, notably Knauf Insulation, LLC v. Johns Manville Corp. (S.D. Ind., filed 2015), where Johns Manville accused Knauf of trade secret misappropriation and patent infringement via a former employee's transfer of proprietary fiberglass insulation technology; the multi-year case has featured denied summary judgment motions and ongoing evidentiary battles as of June 2024.[93][94]