Amines, C12-14-alkyl, C6-10-alkyl phosphates

Endpoint summary

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Absorption rate - oral (%):

50

Absorption rate - dermal (%):

50

Absorption rate - inhalation (%):

100

Additional information

Oral absorption

Based on physicochemical properties:

According to REACH guidance document R7.C (June 2017), oral absorption is maximal for substances with molecular weight (MW) below 500. Water-soluble substances will readily dissolve into the gastrointestinal fluids; however, absorption of hydrophilic substances via passive diffusion may be limited by the rate at which the substance partitions out of the gastrointestinal fluid. Further, absorption by passive diffusion is higher at moderate log Kow values (between -1 and 4). If signs of systemic toxicity are seen after oral administration (other than those indicative of discomfort or lack of palatability of the test substance), then absorption has occurred.

The test substance has a MW above 500 g/mol for the major constituents. The substance is an organic, light yellow liquid, with moderate water solubility of 353 mg/L at 20°C and a log Kow of 2.47.

Based on the R7.C indicative criteria, the oral uptake of the constituents of the test substance is assessed to be moderate, given the average MW not exceeding 500, moderate water solubility and moderate log Kow values.

Conclusion: Overall, based on the above information, the test substance can be expected to have overall moderate absorption potential through the oral route. However, in absence of experimental data, as a default approach a value of 50% has been considered for the risk assessment.

Dermal absorption

Based on physicochemical properties:

According to REACH guidance document R7.C (ECHA, 2017), dermal absorption is maximal for substances having MW below 100 together with log Kow values ranging between 2 and 3 and water solubility in the range of 100-10,000 mg/L. Substances with MW above 500 are considered to be too large to penetrate skin. Further, dermal uptake is likely to be low for substances with log P values <0 or <-1, as they are not likely to be sufficiently lipophilic to cross the stratum corneum (SC). Similarly, substances with water solubility below 1 mg/L are also likely to have low dermal uptake, as the substances must be sufficiently soluble in water to partition from the SC into the epidermis.

The test substance is an organic liquid, with a MW exceeding 100 g/mol, moderate water solubility and a Kow of 2.47. This suggests that the test substance is likely to have a low penetration potential through the skin.

Conclusion: Overall, based on all the available weight of evidence information, the test substance can be expected to undergo a low absorption potential absorption through the dermal route. However, as a conservative approach a value of 50% has been considered for the risk assessment.

Inhalation absorption

Based on physicochemical properties:

According to REACH guidance document R7.C (ECHA, 2017), inhalation absorption is maximal for substances with VP >25 KPa, particle size (<100 μm), low water solubility and moderate log Kow values (between -1 and 4). Very hydrophilic substances may be retained within the mucus and not available for absorption.

Based on experimental vapour pressure of 6 Pa at 20°C, the test substance is considered to have moderate volatility potential under ambient conditions. Further, if at all there is any inhalation exposure, considering the moderate water solubility of the substance, some amount of it is expected to be retained in the mucus and therefore is unlikely to reach the lower respiratory tract for further absorption into the blood stream.

Conclusion: Based on the above information, if exposed the test substance can be expected to undergo moderate absorption through the inhalation route. However, in absence of experimental study data for inhalation route and as a default approach, a value of 100% has been considered for the risk assessment.

Metabolism

Based on QSAR modelling:

The predicted metabolism of the test substance was evaluated using the rat liver S9 metabolism simulator of the OECD QSAR Toolbox v.3.4. According to these simulators, all the five major constituents (present at > 2%) are primarily predicted to undergo aliphatic hydroxylation as first metabolic reaction. For further details, refer to the read across justification.

EXCRETION:

Based on the physico-chemical properties and expected metabolic pathways main excretion of test substance can be expected to be via urine.

BIOACCUMULATION:

Based on the log Kow < 4.5, bioaccumulation potential of the substance is expected to be low.