Experimental and predicted aqueous solubility and vapor pressures of food packaging migrants: 4-n-octylphenol, 4-tert-octylphenol and 4-n-nonylphenol

Abstract

4-n-octylphenol (4-n-OP), 4-n-nonylphenol (4-n-NP) and 4-tert-octylphenol (4-tert-OP) are dangerous chemicals available in food contact materials. In order to be able to evaluate their health risk assessment in terms of exposure pathway, chemodynamic (fate) and transport (migration processes), we studied their physicochemical properties: the aqueous solubility and vapor pressure as a function of temperature. The literature suffers from a lack of data related to these properties. The aqueous solubilities for these molecules were carried out using the dynamic saturation method between 298.15 and 328.15 K. The experimental data are low and range between 10⁻⁶ and 10⁻⁸ in mole fraction. The vapor pressures of alkylphenols were measured using the static and dynamic gas saturation methods. 4-n-OP and 4-n-NP showed the lowest vapor pressure at 298.15 K (lower than 10⁻³ Pa). In a second step, Henry’s law constant and air–water partition coefficient were calculated using experimental aqueous solubility and vapor pressure measurements. All experimental data were compared with available literature data and then with calculated properties issued from UNIFAC thermodynamic model.