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Description of key information

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
100
Absorption rate - inhalation (%):
100

Additional information

In general, a compound needs to be dissolved before it can be taken up from the gastrointestinal tract after oral administration. 1,3-bis[3-(dimethylamino)propyl]urea (CAS 52338-87-1) is found to be essentially miscible in water. This high water solubility means that the substance will readily dissolve into the gastrointestinal fluids, favouring passive diffusion.

The partition coefficient of 1,3-bis[3-(dimethylamino)propyl]urea (Log Pow -8.85 x 10-2) indicates that penetration potential through lipid membranes is low, and that there is low potential to reach the systemic circulation.

Nevertheless, in the absence of specific absorption data, for risk assessment purposes, a worst-case for oral absorption of (21,3-bis[3-(dimethylamino)propyl]urea is used - 100%.

Should it be absorbed, wide distribution of the test substance throughout the body would be expected based on its high water solubility and molecular weight (230.3).

The oral LD50 of the singly-substituted reaction product (MW 145.2, Log Pow -1.581) 3-(dimethylamino)propylurea in rats was approximately 5125 mg/kg (5.0 ml/kg) of body weight, indicating that the doubly-substituted form 1,3-bis[3-(dimethylamino)propyl]urea will have a similar LD50.

1,3-bis[3-(dimethylamino)propyl]urea is marketed in a form that may be applied by spray applications, and therefore there is a potential for aerosols to be formed. Therefore, it is assumed that 1,3-bis[3 -(dimethylamino)propyl]urea can enter the respiratory tract. If 1,3-bis[3-(dimethylamino)propyl]urea reaches the tracheobronchial region, it is likely to be dissolved within the mucus lining of the respiratory tract and to possibly to be absorbed due to its high water solubility and low molecular weight.

Furthermore, due its corrosive potential, it may damage the epithelium lining the respiratory tract, which will further promote systemic uptake of the substance. Therefore, for risk assessment purposes the inhalation absorption of 1,3-bis[3-(dimethylamino)propyl]urea is set at 100%.

1,3-bis[3-(dimethylamino)propyl]urea will dissolve into the surface moisture of the skin. Uptake is facilitated by the relatively low low molecular weight  (230.3) and high water solubility , however the low LogP will mitigate its adsorption. However, due to its corrosive properties, skin integrity may be affected leading to uptake of the substance. Once the skin surface is damaged, 1,3-bis[3-(dimethylamino)propyl]urea will likely be absorbed easily due to its low molecular weight and high water solubility.

Therefore, for risk assessment purposes the dermal absorption of 1,3-bis[3-(dimethylamino)propyl]urea is set at 100%.

The dermal LD50 of the singly-substituted reaction product 3-(dimethylamino)propylurea in rats is greater than 2050 mg/kg of body weight, indicating that the doubly-substituted form 1,3-bis[3-(dimethylamino)propyl]urea will have a similar dermal LD50.

The potential for bioaccumulation of 1,3-bis[3-(dimethylamino)propyl]urea is considered low based on it’s Log Pow (-8.85 x 10-2) and from the results of a bioaccumulation study in fish with the singly-substituted reaction product (MW 145.2, Log Pow -1.581) 3-(dimethylamino)propylurea ((MW 145.2, Log Pow -1.581), where the bioconcentrationfactor (BCF) in carp (Cyprinus carpiol) was found to be less than or equal to 2.3.