## 4 Results
### Normalized Results of the Environmental Impact Assessment  
Since the environmental impact scores of life cycle assessments are often presented in difficult-to-grasp units, we have normalized the results relative to a reference system (Table 14). The environmental footprint assessment of the cosmetic cream revealed several areas of significant environmental impact. The most prominent impact category was eutrophication, freshwater, with a normalized result of 3.000. This indicates that the production and use of the cosmetic cream led to substantial nutrient pollution in freshwater bodies, causing excessive growth of algae and other aquatic plants, which disrupts aquatic ecosystems. Additionally, the resource use for minerals and metals was notably high at 1.856, suggesting a heavy reliance on non-renewable mineral resources and contributing to resource depletion. Ecotoxicity in freshwater also presents a significant concern with a normalized result of 1.416, highlighting the introduction of toxic substances into freshwater ecosystems, harming aquatic life and potentially entering the food chain. The cream's production relies considerably on fossil fuels, as evidenced by resource use, with a fossil impact of 0.965, contributing to the depletion of these non-renewable resources and the associated environmental impacts, such as greenhouse gas emissions. Human health was also impacted, with human toxicity, non-cancer at 0.578, reflecting the presence of harmful chemicals that do not cause cancer, but can still pose health risks. Acidification had an impact score of 0.537, indicating emissions that can harm terrestrial and aquatic ecosystems by lowering pH levels. While climate change impact was lower at 0.344, it still reflects the greenhouse gas emissions associated with the product, contributing to global warming. The formation of ground-level ozone, measured by photochemical ozone formation--human health at 0.273, can cause respiratory problems and other health issues. Eutrophication and marine impacts were measured at 0.233, indicating nutrient pollution in marine environments that affect marine life and ecosystems. Ionizing radiation, human health at 0.228, assesses potential human health risks from exposure to ionizing radiation during the product's lifecycle. Eutrophication, terrestrial, had a score of 0.227, reflecting nutrient pollution on land that affects soil quality and terrestrial ecosystems. Particulate matter, at 0.185, measures the emission of particulate matter, which can cause respiratory and cardiovascular diseases. Human toxicity, cancer, at 0.080, assesses the potential cancer risk to humans from exposure to carcinogenic substances. The impacts on land use and ozone depletion were minimal, with scores of 0.018 and 0.009, respectively, indicating minimal disturbance or conversion of land, and negligible effect on the stratospheric ozone layer. Finally, water use had a meagre impact of 0.008, indicating efficient water use throughout the product's lifecycle. The assessment highlighted significant environmental impacts on freshwater eutrophication, resource use of minerals and metals and freshwater ecotoxicity. Mitigation efforts should focus on reducing nutrient and toxic emissions into freshwater systems and minimizing the use of non-renewable mineral resources. Addressing fossil fuel dependency and the impact of climate change will be crucial for improving the product's environmental footprint. The relative results of the environmental footprint assessment of the cosmetic cream are presented in Figure 2.  
The environmental impact assessment of the cosmetic cream revealed that the most significant contributors to its environmental footprint are gold nanoparticle synthesis and electricity use (Figure 3). Gold nanoparticle synthesis has the highest impact across multiple categories, including freshwater ecotoxicity (1.252), resource use for minerals and metals (1.809), and acidification (0.240). This is due primarily to the resource-intensive nature of gold mining and processing.