Fish processing produces large amounts of fish waste. Instead of disposing of it, it is wiser to recover the valuable resource for high-value-added products. Our study proposed a process using carbon dioxide-acidified water as a green solvent under supercritical conditions to successfully recover collagen/gelatin from the skin and bone of striped catfish. The optimum extraction conditions were obtained at 75 bar, 37 °C, and 24 h. The yields from the dry skin and bone mass were around 37% and 8%, respectively. The extracted products were characterized by Fourier-transformed infrared spectroscopy to study the functional groups, scanning electron microscopy to evaluate the morphology, sodium dodecyl-sulfate polyacrylamide gel electrophoresis to study the protein pattern, UV–vis analysis to measure the absorption peak, and thermal gravimetric analysis to determine the denaturation temperature. The results show the viability of the proposed method on an industrial scale. The characteristics of the extracted product show promising results and potential for being developed further in many applications such as biomaterial engineering in healthcare or natural polymer-based absorbent material for efficient removal of heavy metals from water and wastewater.

Skin‐whitening body lotions are widely used in Cambodia, and mercury (Hg) has been reported in such products in Phnom Penh in earlier surveys, but no recent measurements exist. This study aimed to determine the concentrations of Hg, cadmium (Cd), and lead (Pb) in whitening body lotions sold in local markets in Phnom Penh and to assess the dermal exposure arising from their use. Fifteen commonly used brands were sampled; three independently purchased containers of each were digested with HNO ₃ for Hg and sequentially with HNO ₃ , H ₂ SO ₄ , and HClO ₄ for Pb and Cd, followed by analysis using atomic absorption spectrophotometry, with hydride vapor generation for Hg. Hg was quantified in three of the fifteen brands, at 9.7480, > 4.5040, and 1.5341 mg/kg, all exceeding the ASEAN limit of 1.0 mg/kg; the remaining twelve brands fell below the reporting limit of 1.0 mg/kg and are therefore compliant. Pb was quantified in two brands, at 6.5930 and 6.7035 mg/kg, both well below the ASEAN limit of 20.0 mg/kg, with the remaining thirteen below the method limit of quantification of 5.1009 mg/kg. Cd was not detected in any brand. Exposure was estimated as the systemic exposure dose and expressed as a hazard quotient, and the amount applied per day was compared with the cutaneous permitted daily exposures of ICH Q3D(R2), separately for the two application patterns reported by 286 users: arms and legs only (70.28%) and whole body (29.72%). Four of the five quantified brand‐metal combinations exceeded 1 in hazard quotients under every base‐case scenario, reaching 8.18 for Hg in one brand, and the same four exceeded the cutaneous permitted daily exposure under whole‐body application. These are screening‐level indications of concern rather than predicted clinical effects and are sensitive to the assumed dermal absorption. Hg exceeding the ASEAN limit in three of fifteen brands, at up to nearly ten times the limit, warrants regulatory attention and consumer awareness.