Optimized Approach for Measuring Ethylene Oxide in Mobile Source Exhaust.

There is a growing awareness of the health impacts of ethylene oxide (EtO) and its role as a carcinogenic and mutagenic air contaminant of concern. Given the need to better understand EtO emissions and associated health effects, it is imperative to overcome the significant challenges associated with EtO measurement in complex air matrices, such as combustion emissions. This work focused on addressing these challenges by evaluating the utility of widely used canister-based EtO ambient measurement approaches, EPA Methods TO-15 and TO-15A, to investigate the presence of EtO in heavy-duty diesel vehicle (HDDV) exhaust.

Gas and particle emissions from rifle and pistol firing.

Emissions were sampled from firing an M4 carbine rifle and a M9 (military issue of Beretta 75 FS 9 mm pistol) to develop sampling methods and assess potential exposures and range contamination issues. Breech and muzzle emissions were sampled from the rifle when firing M855A1 ammunition (lead (Pb)-free slugs) in single- and triple-shot burst mode and from single pistol shots when firing 9 mm XM1152 ammunition (not Pb-free). Emissions were sampled for carbon monoxide (CO), carbon dioxide (CO), methane, hydrogen cyanide, ammonia, particulate matter by size, polycylic aromatic hydrocarbons, and volatile organics.

Pilot-Scale Thermal Destruction of Per- and Polyfluoroalkyl Substances in a Legacy Aqueous Film Forming Foam.

The destruction of per- and polyfluoroalkyl substances (PFAS) is critical to ensure effective remediation of PFAS contaminated matrices. The destruction of hazardous chemicals within incinerators and other thermal treatment processes has historically been determined by calculating the destruction efficiency (DE) or the destruction and removal efficiency (DRE). While high DEs, >99.

Assessment of Chemical Facility Ethylene Oxide Emissions Using Mobile and Multipoint Monitoring.

Ethylene oxide (EtO) is a hazardous air pollutant that can be emitted from a variety of difficult to measure industrial sources, such as fugitive leaks, wastewater handling, and episodic releases. Emerging next generation emission measurement (NGEM) approaches capable of time-resolved, low parts per billion by volume (ppbv) method detection limits (MDLs) can help facilities understand and reduce EtO and other air pollutant emissions from these sources yielding a range of environmental and public health benefits. In October 2021, a first of its kind 4-day observational study was conducted at an EtO chemical facility in the midwestern United States.

Combustion of C and C PFAS: Kinetic modeling and experiments.

A combustion model, originally developed to simulate the destruction of chemical warfare agents, was modified to include C-C fluorinated organic reactions and kinetics compiled by the National Institute of Standards and Technology (NIST). A simplified plug flow reactor version of this model was used to predict the destruction efficiency (DE) and formation of products of incomplete combustion (PICs) for three C and C per- and poly-fluorinated alkyl substances (PFAS) (CF, CHF, and CF) and compare predicted values to Fourier Transform Infrared spectroscopy (FTIR)-based measurements made from a pilot-scale EPA research combustor (40-64 kW, natural gas-fired, 20% excess air). PFAS were introduced through the flame, and at post-flame locations along a time-temperature profile allowing for simulation of direct flame and non-flame injection, and examination of the sensitivity of PFAS destruction on temperature and free radical flame chemistry.