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Administrative data

Link to relevant study record(s)

Description of key information

Considering the physico-chemical properties of oxybenzone, i.e., low molecular weight (228.24 g/mol), medium log Pow value (3.45), low vapor pressure (ca. 1 x 10E-3 Pa), and the coarse particle size (mass median diameter >100 µm), the absorption of oxybenzone is expected to mainly occur via dermal and oral route. Whereas oral absorption is rapid upon dermal application of humans up to 2% may become systemically available as shown by Treffel P, et al., 1996 and H. Gustavsson Gonzalez, et al., 2002. However, as R. Jiang et al. (1999) showed in an in-vitro model that up to about 10% dermally (SCCP, 2008) applied oxybenzone could eventually penetrate this value is used in a worst case approach as maximum dermal penetration rate.

Key value for chemical safety assessment

Bioaccumulation potential:
low bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
10

Additional information

Considering the physico-chemical properties of oxybenzone, i.e., low molecular weight (228.24 g/mol), medium log Pow value (3.45), low vapor pressure(ca. 1 x 10-3Pa), and the coarse particle size (mass median diameter >100 µm),the absorption of oxybenzone is expected to mainly occur via dermal and oral route. After absorption, oxybenzone can be metabolized to two intermediates, 2,3,4-trihydroxybenzophenone (THB) (via 2,4-dihydroxybenzophenone (DHB)) and 2,2’-dihydroxy-4-methoxybenzophenone (DHMB). End metabolites are same, whereas species difference was shown between rat and mouse regards DHB presence in rat, but experimental data indicated the mouse is a closer metabolic match to human compared with rat.The liver contained the highest amount of oxybenzone and metabolites followed by the kidney, spleen and testes, respectively.Available data suggested that oxybenzone will be excreted mainly via urine and/or by feces, in the form of conjugation and parent compounds. Many studies in rats have demonstrated substantial excretion both in urine (67%) and faeces (21%), while the studies on human reveal that the excretion of the substance is much lower, ranging from ca. 0.4 % to 10 % at the maximum. Thus it was proposed that oxybenzone eventually may accumulate in human body as there is evidence that the volunteers excreted the compound 5 days after the last application in a study. Upon dermal application of humans up to 2% may become systemically available as shown by Treffel P, et al., 1996 and H. Gustavsson Gonzalez, et al., 2002. However, as R. Jiang et al. (1999) showed in anin-vitromodel that up to about 10% dermally (SCCP, 2008) applied oxybenzone could eventually penetrate this value is used in a worst case approach as maximum dermal penetration rate.