In wastewater environments, anaerobic bacteria frequently produce hydrogen sulfide, which poses a considerable threat to the durability of concrete structures through accelerated corrosion. Protective coatings are routinely applied to mitigate this issue and preserve structural integrity. Conventional coatings such as epoxy and polyurethane are prevalent due to their efficacy in corrosion prevention. However, these traditional coatings are associated with significant environmental drawbacks, including the emission of volatile organic compounds (VOCs) and other pollutants that adversely affect environmental quality. In response to escalating environmental concerns, it is imperative to investigate alternative materials that offer reduced environmental impact. Magnesium hydroxide emerges as a viable alternative for corrosion protection, presenting several advantages over conventional coatings. It is characterized by lower toxicity and does not emit harmful substances during application or service. Recent advancements in production techniques have revealed that magnesium hydroxide can be derived from seawater, suggesting a more sustainable approach. Utilizing seawater as a source of magnesium hydroxide can considerably reduce the environmental impact associated with its production, given the abundant and renewable nature of this resource. This study aims to assess the environmental benefits of seawater-derived magnesium hydroxide coatings compared to commercially available magnesium hydroxide coatings through a comprehensive life cycle assessment (LCA). The LCA was conducted using SimaPro software, a leading tool for evaluating the environmental impacts of products and processes. A cradle-to-gate boundary was established for this analysis, incorporating data from the Ecoinvent 3.9.91 database and employing the ReCiPe Endpoint (H) V1.13 methodology to evaluate various impact categories. The functional unit for this assessment was defined as the quantity of coating required to cover a single face of a 0.01 m² concrete cube specimen. The environmental impact data were extrapolated to a scale representative of a Department of Public Works and Highways (DPWH) flood control project to contextualize the findings. This approach provides a more practical evaluation of the potential impacts of these coatings in large-scale applications. It is hypothesized that coatings formulated with higher proportions of seawater-derived magnesium hydroxide will demonstrate markedly lower environmental impacts than their commercially available counterparts. This study seeks to elucidate the benefits of incorporating seawater-derived magnesium hydroxide into construction practices, advancing the adoption of more sustainable materials and contributing to enhanced environmental stewardship within the construction industry. The findings aim to facilitate the transition towards eco-friendly solutions in corrosion protection and foster advancements in sustainable construction practices.