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Description of key information

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 (May 2014), 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 having a MW of ranging from 652 -680 g/mol for the major constituents (average: 663 g/mol). The substance is a solid, with low water solubility of 4.8 mg/L at 20°C (based on CMC) and an estimated log Kow of 4.32.

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

Conclusion:Overall, based on the above information, the test substance can be expected to overall have low absorption potential through the oral route. However, as a conservative approach a default 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 thestratum 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 soild, with an MW exceeding 100 g/mol, low water solubility and an estimated log Kow greater than 3. 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 have a low absorption potential absorption through the dermal route. Therefore, as a conservative approach a default 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 3.87E-7 Pa at 20°C, the test substance is considered to have low volatility potential under ambient conditions. Therefore, the substance is expected neither to be available for inhalation as vapours. Further, if at all there is any inhalation exposure, considering the low water solubility of the substance, it is not expected to be retained in the mucus and almost the entire test substance amount is likely to reach the lower respiratory tract followed by absorption into the blood stream.

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

BIOACCUMULATION:

Based on the low water solubility and an estimated log Kow < 4.5, bioaccumulation potential is expected to be low.