## 3 Inventory Data
### Inventory Data for the Production of the Base Cream
The Pentylene glycol, although slightly different in structure from propylene glycol, was modelled using the same dataset, \"Market for propylene glycol, liquid!Cutoff, U*, due to their similar properties and applications. Carbomers are synthetic high molecular-weight polymers derived from acrylic acid [21; 22], used commonly as thickeners, stabilizers and emulsifiers in cosmetic products. They can absorb up to 1000 times their weight in water, making them effective in maintaining product consistency, and their properties are pH sensitive. Carbomers are considered safe by regulatory bodies such as the FDA and the EU's Cosmetics Regulation, though some individuals may experience skin irritation. The production of carbomers was modelled using the \"Market for acrylic acid!acrylic acid!Cutoff, U* dataset, representing acrylic acid production via the two-step oxidation of propylene. Glycerol istear, derived from vegetable sources, is used commonly in cosmetics as an emulsifier and skin-conditioning agent. It is synthesized by esterifying glycerol and stearic acid, where the hydroxyl group of glycerol reacts with the carboxyl group of stearic acid to form glyceryl stearate and water. For 1 kg of glyceryl stearate, 0.467 kg of glycerol and 0.533 kg of stearic acid are required. The Eoinvent datasets used are \"Market for stearic acid!Cutoff, U* and \"Market for glycerine!Cutoff, U*. Isopropyl issotearate, an ester of isopropyl alcohol and issotexaric acid, is used as a skin-conditioning agent and embilient in cosmetics. It is a lightweight, non-greasy liquid, absorbed easily by the skin, and found commonly in lotions, creams and serums. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Data** & **Quantity** & **Unit** & **Dataset** \\ \hline Cetaaryl ethylhexanoate & 0.325 & kg & *Market for esters of versatile acid!esters of versatile acid!Cutoff, U* \\ \hline Borago officinalis seed oil & 0.325 & kg & *Market for cottonseed oil, crude!Cutoff, U* \\ \hline Prunus amygdala dulcis oil & 0.325 & kg & *Linseed oil, refined, at oil mill* \\ \hline Onentohennis oil & 0.325 & kg & *Market for vegetable oil, refined! vegetable oil, refined!Cutoff, U* \\ \hline Macadamia integrifolia/Tetraphyll seed oil & 0.325 & kg & *Market for vegetable oil, refined! vegetable oil, refined!Cutoff, U* \\ \hline Mixture of PEG-8, Tocopherol Ascorbyl Palmitate, Ascorbic Acid, and Citric Acid & 0.065-0.5 & kg & 50\% of the total flow, we used ascorbic acid!Market for ascorbic acid! ascorbic acid!Cutoff, U* \\ \hline  & 0.065-0.5 & kg & 50\% of the total flow, we used citric acid: *Market for citric acid!citric acid!citric acid!Cutoff, U*. \\ \hline Polymethacrylate, Propylene Glycol and Palmitoyl Tripeptide-1 & 0.650 & kg & *Market for propylene glycol, liquid!propylene glycol, liquid!Cutoff, U* \\ \hline Sodium Hydroxide & 0.254 & kg & *Market for sodium hydroxide, without water, in 50\% solution state!sodium hydroxide, without water, in 50\% solution state!Cutoff, U* \\ \hline \hline \end{tabular}
\end{table} 
Table 7: _Cont._Its production was modelled using the Ecoinvent dataset >>Market for esters of versatile acid | Cutoff, U<<. Versatic acid was chosen, due to its functional and structural similarities to the fatty acid precursor, isostearic acid. As a synthetic branched carboxylic acid, Versatic acid aligns closely with the branched-chain structure of isostearic acid, influencing production processes and environmental profiles in a comparable manner. Ethylhexyl isononanoate is a clear, colorless ester used as an embilient and conditioning agent in cosmetics. It improves texture and spreadability in moisturizers, suscreens and hair conditioners, without leaving a greasy residue. It is produced by reacting isononanoic acid with 2-ethylhexanol. The production was modelled using the Ecoinvent dataset >>Market for esters of versatile acid | Cutoff, U<<, due to its suitability for representing the esterification process.