Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 270-451-8 | CAS number: 68440-34-6
Adsorption / desorption
Administrative data
Link to relevant study record(s)
Description of key information
The substance has potential to adsorb.
Key value for chemical safety assessment
Additional information
No experimental adsorption data are available for Fatty acids, tallow, zinc salts. The substance, is produced from natural fatty materials, which is a mixture of stearic (C18) and palmitic (C16) acid and monounsaturated C18 fatty acids. It consists of up to 90% natural fatty acid and up to 10% of zinc.
The adsorption potential of the fatty acids was estimated using KOCWIN v2.00. Based on log Kow, log Koc values of 4.1, 4.7 and 4.4 were obtained for palmitic acid, stearic acid and oleic acid, respectively. With the molecular connectivity index (MCI), log Koc values were 3.5 (palmitic acid) and 4.1 (stearic and oleic acid). The values indicate that the fatty acids have potential to adsorb to solid organic matter.
For metals, adsorption/desorption translates in the distribution of the metal between the different fractions of the environmental compartment, e.g. the water (dissolved fraction, fraction bound to suspended matter), soil (fraction bound or complexed to the soil particles, fraction in the soil pore water, etc.). This distribution between the different compartments is translated in the partition coefficients between these different fractions. Partition coefficients for zinc in freshwater has been reviewed in the Risk Assessment Report for zinc metal (ECB, 2008). Based on the extensive experimental evidence, a partition coefficient for the distribution between solid particulate matter and water (Kpsusp) of 5.04 (log value) has been defined for EU waters and used throughout the risk assessment.
The partition coefficient for the distribution between sediment and water (Kpsed) was estimated in the Risk Assessment Report from that for particulate matter, as follows: Kpsed = Kpsusp/ 1.5, based on the average difference in concentrations of zinc and other metals in both media. For zinc this results in a Kpsedof 73000 L/kg (ECB, 2008).
The marine Kd was derived based on data from several marine waters. The geomean value for zinc in seawater is 6010 l/kg (log value 3.78).
For soil, a solids-water partitioning coefficient of 158.5 L/kg (log value 2.2) was determined experimentally on 11 American soils. This value was used in the risk assessment for zinc.
Study records on partition coefficients for zinc are given under Section 5.6 of the technical dossier.
Conclusion
Fatty acids as well as zinc have potential to adsorb to solid and sediment organic matter, therefore also for Fatty acids, tallow, zinc salts adsorption is to be expected.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
