Bis(dibutyldithiocarbamato-S,S')copper

Endpoint summary

Description of key information

No experimental toxicokinetic study is available on CDBC. However, as per REACH guidance document R7.C, information on absorption, distribution, metabolism and excretion may be deduced from the physical-chemical properties and QSAR predictions.

CDBC is expected to be well absorbed by oral route and inhalation (100%), but lesser by dermal route (10%).

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

10

Absorption rate - inhalation (%):

100

Additional information

The following remarks on the toxicokinetics of CDBC are based on the available studies. Experimental toxicokinetic studies were not available. However, as per REACH guidance document R7.C, information on absorption, distribution, metabolism and excretion may be deduced from the physical-chemical properties, including:

-Molecular weight = 472.4 g/mol

-Water solubility = 1µg/L

-Partition coefficient Log Kow = 4.7

-Granulometry : average diameter (D4,3) > 1000µm.

 

ABSORPTION

Oral absorption :

The high value of log Kow (>4) and the low solubility (<1 mg/L) of CDBC are favorable for a low oral absorption. However, according to the model "Intestinal absorption (human)", 87% of the substance is absorbed (pkCSM).

100% of oral absorption is taken into account for the risk assessment.

 

Dermal absorption :

A Log Kow higher close to 4 suggests that the rate of penetration of the substance may be limited by the rate of transfer between the stratum corneum and the epidermis. This is confirmed by the IH skin perm (QSAR) but 0% of the administrated substance was absorbed in the viable epidermis. Indeed, the dermal absorption of CDBC is expected to be low: 10% of absorption is taken into account for the risk assessment. CDBC is not a skin sensitizer based on the LLNA available (no evidence of dermale absorption).

Inhalation absorption :

Based on the high granulometry of the substance, no high absorption by inhalation is expected. But in absence of inhalation data, 100% of absorption is taken into account for the risk assessment (worst case).

 

DISTRIBUTION

Based on the chemical and physical parameters, a wide distribution of CDBC is not expected if the substance is absorbed. As the substance is lipophilic, it is likely to distribute into cells and the intracellular concentration may be higher than extracellular concentration particularly in fatty acid. According to the QSAR prediction, a moderate distribution is expected, and the substance is able to pass the BBB (pkCSM)

 

METABOLISM

No specific information was found on metabolism of CDBC.

 

EXCRETION

Due to the low water solubility and a moderate molecular mass (near to 500 g/mol), if CDBC is absorbed, the excretion of CDBC in the urines is not expected. This is confirmed by the QSAR prediction (pkCSM), in which a low renal and hepatic clearance is expected. So, an excretion via bile and faeces is possible.