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Description of key information

Key value for chemical safety assessment

Additional information

There are no toxicokinetic studies available with the test substance. Therefore, the following assessment of the toxicokinetic behavior is based on the physicochemical properties of the test substance and the results from existing toxicological studies with the test substance.

 

Relevant physicochemical properties of the substance:

- substance is solid

- volatility: negligible; negligible vapour pressure at 20 and 50°C (<0.000001 hPa), melting point 133.5 °C

- molecular weight: 217.1992 g/mol

- logPow: -0.7 at 23°C and at pH = 1.3, -1.5 at 23°C and at pH = 2.3

- water solubility: 667 g/l at 23°C

 

Interpretation of data from acute toxicity studies and repeated dose toxicity (RDT) studies:

There are data on acute oral toxicity in rats (LD50 > 300 < 2000 mg/kg bw; BASF SE, 2010) and acute dermal toxicity in rats (LD50 > 2000 mg/kg bw; BASF SE, 2010). There are also data on oral RDT available, with a NOAEL (rat) = 150 mg/kg bw (GINC). After single or repeated oral application signs of systemic toxicity were observed indicating absorption of the test substance by this exposure route. After single dermal application no mortalities, clinical effects, specific target organ toxicity or any other changes were observed. This result is suggestive of a limited dermal absorption of the test substance.Supporting to the results from toxicological studies with oral administration, the properties of the test substance meet the physiological factors for GIT absorption (MW < 500 g/mol and moderate log POWbetween -1 and 4). According to the Danish (Q)SAR Database (EPI Suite, DERMWIN v2.09) and supporting to the lack of systemic effects in the acute toxicity study with dermal application, the dermal absorption of the test substance is estimated to be very low with an estimated Kp value of 2.78E-05 cm/hr. In contrast, the sensitising effect observed in a Local Lymph Node Assay with dermal application in mice (BASF SE, 2010) proved a certain dermal penetration of the test substance or metabolites thereof.

Based on the measured log Pow (-1.5 to -0.7) and the measured BCF (<4.1) of 4-nitrotoluene-2-sulphonic acid bioaccumulation is not expected.