ACS Chemical Health & Safety最新文献

We present here a narrative of an incident that occurred in a chemistry laboratory while purifying benzene using a distillation apparatus. The incident resulted in an injury to a graduate student and a fire that caused approximately $3.5 million in damage including repair/refurbishment costs. Unfortunately, due to the extent of the fire, a direct cause of the incident could not be determined. The lessons learned from this incident that could have potentially prevented the incident altogether, or at least reduced damage, include performing a risk assessment of both the experiment and the situation at the time, maintaining proper housekeeping of the lab, maintaining an updated and accurate chemical inventory, checking in on long duration experiments, always calling for back-up, ensuring the lab and buildings are up to code, wearing proper personal protective equipment, and always calling 911 in an emergency.

Particles and volatile organic compounds (VOCs) have been detected emitting from material extrusion 3D printing, which is widely used in nonindustrial environments. However, vat polymerization 3D printing that is also commonly used has yet to be well-characterized for its emissions. In this study, we measured particle and VOC emission rates from stereolithography (SLA) 3D printing during print and post-processing wash and cure processes individually using a standardized testing method for 3D printer emissions in an exposure chamber. We observed minimal particle emissions and identified 30 to over 100 individual VOCs emitted from each operating phase, some of which accumulated after the printing ended. The total VOC emissions from SLA processes were higher than typical levels from material extrusion 3D printing, and the emission rate could be over 4 mg/h. Major VOCs emitted were associated with the resin and chemicals used in print and post-processing procedures, which included esters, alcohols, aldehydes, ketones, aromatics, and hydrocarbons. Emissions from post-processing units were lower than those from printing but also included chemicals with health concerns. The emitted mixture of sensitizers, carcinogens, irritants, and flammable chemicals may present a hazard for indoor air quality and human health. The estimated personal exposure to total VOC and some specific VOCs of concern to human health, like formaldehyde and naphthalene, exceeded the recommended indoor levels (e.g., California Office of Environmental Health Hazard Assessment), potentially causing irritation and other health impacts for 3D printer users.

The Grignard reaction has been one of the most versatile workhorses for synthetic organic chemists for more than a century. Typically, the preparation of Grignard reagents and their subsequent reactions require anhydrous solvents and a protective inert atmosphere. A recent report showed that the reactions could be performed under mechanochemical conditions by ball-milling magnesium metal, an organic halide, and a small amount of an ethereal solvent together followed by the addition of an electrophile. Excellent results were reported for a broad range of substrates even when the reaction was performed under the ambient atmosphere, making the process highly appealing to a wide synthetic community. In this commentary, some safety aspects of this mechanochemical Grignard reaction are pointed out so that appropriate risk management plans can be devised to ensure its safe use.

A key engineering control to prevent overexposure to laboratory chemicals is the use of enclosed chemical processes connected to exhaust ventilation. The vast majority of the US states have adopted the International Mechanical Code which provides guidance on the design of mechanical systems, including exhaust ventilation systems. This code contains Chapter 510, which addresses hazardous exhaust systems. This article explains where and how this often misunderstood chapter applies to research laboratory exhaust systems.

Pesticide product labels are critical for consumers to safely and legally use pesticides. Because residue levels in the environment are relatively high immediately after pesticide application, avoiding contact with residues in the emitted area after the application could help reduce pesticide exposure. However, the safety instructions on pesticide product labels after pesticide application are insufficient. To minimize pesticide exposure and promote integrated pest management, we improved pesticide product labels by introducing recommended safe durations (close windows and doors and stay off lawns after pesticide application), which were proposed using screening models and specific to individual active ingredients. The results showed that children’s exposure to residues in the lawn environment can be reduced by over 30% for many currently used pesticides with a recommended safe duration of 3 d. Rainfall or irrigation events can help reduce exposure to hydrophilic pesticides, and high temperatures can further reduce the exposure because of the enhanced overall dissipation process of pesticides in the lawn environment. Based on the simulations, we improved the pesticide product label by adding recommended safe durations and reducing children’s exposure to residues, providing the effects of weather conditions and irrigation activities on the reduced pesticide exposure, and clarifying the difference between exposure and adverse health risks. The proposed safety instructions can be customized for individual active ingredients and easily understood/followed by consumers, which can help minimize children’s exposure to residues and promote integrated pest management.

In collaboration with C&EN

The University of California Center for Laboratory Safety held its fifth biennial Workshop on Laboratory Safety in May of 2021. The Workshops on Laboratory Safety provide a unique forum for researchers and safety professionals to exchange perspectives and ideas. The theme of this year’s workshop was Advancing Safety in Teaching and Research Laboratories. Speakers emphasized the importance of an enlightened leadership style, the significance of integrating risk assessments into the science curriculum, and the impact of human factors on risk minimization. Furthermore, speakers discussed innovative programs to engage Principal Investigators in organizational safety culture and computational approaches for defining the toxicity of chemical compounds. Panels discussed two topics: student-led safety initiatives and the long-term impact of COVID-19 on academic life, research, and lab safety. Finally, 11 workgroups examined current safety topics over the 3 day course of the workshop culminating in final presentations on their recommendations. This paper summarizes all presentations and lists key resources from each discussion.

Inherent to the work carried out at institutions of higher education is a set of diverse health and safety risks, which include the use of a variety of potentially hazardous materials. To manage these hazards, colleges and universities typically maintain Environmental Health and Safety (EHS) programs, but objective models for determining the typical amount of organizational resources dedicated to EHS programs are lacking. Summarized here are a series of iterative modeling efforts based on benchmarking data provided by the members of the Campus Safety, Health, and Environmental Management Association (CSHEMA), combined with publicly available institutional data, to produce a series of predictive models for EHS program resourcing. Linear and multiple regression analysis techniques were utilized to develop the models to estimate industry-average college and university EHS program staffing and expenses. Interestingly, the subset of recurrent key predictors identified through these efforts, such as the total net assignable area (TNASF) and the research laboratory area, includes measures that many EHS professionals do not typically have readily available. Although these models do not address the ultimate outcomes achieved by any EHS program, they can assist decision makers with determining a representative level of staffing and resources needed to support university EHS programs.