3-(2-hydroxyethyl)-p-phenylenediammonium sulphate

Endpoint summary

Description of key information

In a dermal absorption study performed according to OECD guideline 428, the absorbed dose or the amount that had penetrated through the skin (receptor fluid and receptor rinse) was 0.13% (0.58 ug equiv/cm2) of the applied dose under oxidative conditions. The dermal bioavailability of hydroxyethyl-p-phenylenediamine sulfate was 0.57% (2.46 ug equiv/cm2) under oxidative conditions. The absorbed dose or the amount that had penetrated through the skin (receptor fluid and receptor rinse) was 0.16% (0.70 ug equiv/cm2) of the applied dose under non-oxidative conditions. The dermal bioavailability of hydroxyethyl-p-phenylenediamine sulfate was 0.49% (2.12 ug/cm2) under non-oxidative conditions.  

The absorption, distribution and excretion of hydroxyethyl-p-phenylenediamine sulfate was studied in an in vivo study after dermal and oral administration. 14C labelled 2,5 -diaminophenylethanol sulphate (hydroxyethyl-p-phenylenediamine sulfate) was applied to the dorsal skin of rats for 30 minutes then washed off. The test substance was integrated into two different hair dyeing formulations (I and II) or was evaluated as a solution in water. Hair dyeing formulation II was mixed with Welloxon (containing 9% hydrogen peroxide) before application. Oral application of the test substance was used as a reference. An additional experiment was performed to determine the blood level after peroral application.

The mean percutaneous absorptions of the test substance were very low in each of the three experiments. (0.063% for hair dyeing formulation I, 0.077% for hair dyeing formulation II plus hydrogen peroxide, 0.124% for the test substance solution). The 14C labelled compound was excreted to a larger extent via urine (75-86% of the eliminated 14C) and to a lesser extent via faeces (14-25%). The mean excretion within the first 24 hours was fast (87-95% of the eliminated 14C in experiments A to C). Mean 14C concentrations of blood and the 14 analysed organs in experiments A to C were all near or below the detection limit after 72 hours. After oral administration of the test substance the 14C labelled compound was excreted to a larger extent via urine (86% of the eliminated 14C) and to a lesser extent via faeces (14%). The 14C compound excreted within the first 24 hours equated to 99%. Highest 14C cncentrations were detected in the thyroid, liver and adrenals. Lowest detected in testes, fat, femur. The blood level was highest after 35 minutes post administration and declined with an initial half-life of ~50 minutes.

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Absorption rate - dermal (%):

0.16