The autoxidation of polyether-polyurethane open cell soft foam: An analytical aging method to reproducibly determine VOC emissions caused by thermo-oxidative degradation.

We present a new method for investigating the oxidation and emission behavior of air-permeable materials. Employing this method, a differentiated statement can be made about the extent to which critical volatile organic compounds (VOCs) such as formaldehyde, acetaldehyde, and acrolein are contained in the material as impurities or formed by thermo-oxidative degradation of the polymer matrix in the use phase. The parameters affecting methods of VOC analysis are reviewed and considered for the developed method. The molecular mechanisms of VOC formation are discussed. Toxicological implications of the reaction kinetics are put into context with international guidelines and threshold levels. This new method enables manufacturers of cellular materials not only to determine the oxidative stability of their products but also to optimize them specifically for higher durability. ENVIRONMENTAL IMPLICATION: Cellular materials are ubiquitous in the technosphere. They play a crucial role in various microenvironments such as automotive interiors, building insulation, and cushioning. These materials are susceptible to oxidative breakdown, leading to the release of formaldehyde, acetaldehyde, and acrolein. The ecotoxicological profiles of these compounds necessitate monitoring and regulation. The absence of reproducible and reliable analytical methods restricts research and development aimed at risk assessment and mitigation. This work significantly enhances the toolbox for optimizing the oxidative stability of any open-cell cellular material and evaluating these materials in terms of their temperature-dependent oxidation and emission behavior.

Decontamination of disposable respirators for reuse in a pandemic employing in-situ-generated peracetic acid.

BACKGROUND: During shortages of filtering face pieces (FFP) in a pandemic, it is necessary to implement a method for safe reuse or extended use. Our aim was to develop a simple, inexpensive and ecological method for decontamination of disposable FFPs that preserves filtration efficiency and material integrity. MATERIAL AND METHODS: Contamination of FFPs (3M Aura 9320+) with SARS-CoV-2 (1.15 × 104 PFUs), Enterococcus faecium (>106 CFUs), and physiological nasopharyngeal flora was performed prior to decontamination by submersion in a solution of 6 % acetic acid and 6 % hydrogen peroxide (6%AA/6%HP solution) over 30 minutes. Material integrity was assessed by testing the filtering efficiency, loss of fit and employing electron microscopy. RESULTS AND DISCUSSION: Decontamination with the 6%AA/6%HP solution resulted in the complete elimination of SARS-CoV-2, E. faecium and physiological nasopharyngeal flora. Material characterization post-treatment showed neither critical material degradation, loss of fit or reduction of filtration efficiency. Electron microscopy revealed no damage to the fibers, and the rubber bands' elasticity was not affected by the decontamination procedure. No concerning residuals of the decontamination procedure were found. CONCLUSION: The simple application and widespread availability of 6%AA/6%HP solution for decontaminating disposable FFPs make this solution globally viable, including developing and third world countries.

VOC emissions from particle filtering half masks - methods, risks and need for further action.

Investigations into volatile organic compound (VOC) emissions from polymer fleeces used in particle filtering half masks were conducted and evaluated against the German hygienic guide value for total volatile organic compounds and the "Lowest Concentration of Interest" for construction products. All masks showed emission of Xylene. In 94 % of samples, up to 24 additional aromatic compounds were found. 17 % of samples showed terpenes, 53 % emitted aldehydes, 77 % exhibited caprolactam and 98 % released siloxanes. All masks exceeded the TVOC hygienic guidance value level 5 of 10 mg/m³. Emission levels were investigated for masks immediately after their packages were opened and for masks that were "vented" for two weeks. Further, the emissions were repeatedly measured to investigate the decrease of emissions. An exponential decline was observed and a fitting function was calculated. The influence of the two commonly gas chromatograph (GC) hyphenated detectors, mass spectrometer (MS) and flame ionization detector (FID) on the VOC quantification, as well as the influence of temperature on the emission of VOCs were investigated. A statistical analysis of emission value differences for Notified Bodies was conducted and CE 2163 and 2020-1XG proved to be outliers.