Whilst subtractive manufacturing has been de-risked significantly over recent decades, the emergence of new unfamiliar materials is proving to be a significant challenge for social sustainability. Given this rapidly evolving landscape, this review serves to outline the current available data on the occupational health implications of various existing and emerging material species, ranging from radioactive metals to composite materials. A structured search of sources up to January 2025 was conducted using databases such as Google Scholar, PubMed and Web of Science in addition to various authoritative occupational health reports, prioritising the literature directly pertaining or analogous to machining-related hazards. Evidence highlights the complexity of the machining environment, with occupational hazards ranging from toxicological factors to fire risks (i.e., due to swarf pyrophoricity). Case studies outline both relatively benign pathologies (e.g., dermatitis and sensitisation) and much more severe health complications (e.g., carcinogenicity, systemic organ damage and death), underscoring the need for continuous assessment and updating of exposure controls, even for materials traditionally regarded as safe.

Due to recent developments across the aerospace, power generation and defense sectors, the demand for flat-surfaced components with extremely high surface quality is rapidly increasing. In this regard, although abrasive machining processes often produce fine, contaminated swarf that is frequently relegated to landfill, these processes remain critical for the engineering sector. Motivated by increasing sustainability and circularity pressures, this narrative review examines the current state of the art in recycling and repurposing the chips, tooling and cutting fluids that are typically generated or consumed within grinding processes. In doing so, a number of methodologies for extracting useful materials from swarf slurries are identified, including pyrometallurgical routes (applied successfully to Ni–Co alloys, for example), hydrometallurgical strategies (e.g., iron leaching from ferrous swarf) and, in the case of non-metallic materials such as CMCs and CFRPs, chemical processing methods. Various means of separating abrasive constituents and removing contaminants from grinding swarf are also highlighted, within which centrifugation and heat treatment are found to be particularly useful for non-ferrous materials such as titanium alloys or composites, whilst ferrous materials are largely magnetically separated. Prospective applications for spent abrasive tooling are also explored, including reuse as shot, waterjet machining feedstock, road surface additives, or mortar in the context of cement production. Likewise, heat- and radiation-based strategies for prolonging cutting-fluid life are highlighted, and their associated sustainability benefits and limitations discussed, despite ultimate disposal still being relegated to fuel usage or landfill. Ultimately, this review identifies the scarcity of grinding-specific recycling process data and highlights the need for robust, publicly accessible recycling strategies for novel material systems.