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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 619-372-6 | CAS number: 98730-04-2
Adsorption / desorption
Administrative data
Link to relevant study record(s)
Description of key information
Two reliable OECD 106 Guideline studies investigated the adsorption behaviour of benoxacor onto soil. Spare (1987) conducted the experiment with four sterilised soils and reported Koc values in the range 42.3-176.5 L/kg. Reischmann (1997) reported Koc values of for five soils between 210.9 and 340.4 L/kg. It is proposed to use the overall mean value of 218 L/kg for the chemical safety report.
Key value for chemical safety assessment
- Koc at 20 °C:
- 218
Additional information
Two studies investigated the adsorption behaviour of benoxacor onto soil. Spare (1987) performed a GLP-compliant study with four soils equivalent to the OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method). The resulting Koc values ranged (42.3-176.5 L/kg) with a mean value of 128.5 L/kg.
In a second study, Reischmann (1997) investigated the adsorption/desorption behaviour of 14C-benoxacor in five different soil types. The mean adsorption constant based on the organic carbon content (OC) of all soils was determined to Koc = 290 L/kg (range 210.9 to 340.4 L/kg). The study is considered to be reliable.
The soil adsorption values reported by both studies are presented in the Table below.
Soil |
Organic carbon |
Adsorption [mL/g] |
Reference |
|
Type |
[%] |
Kd |
Koc |
|
Maryland clay |
2.8 |
4 |
140 |
Spare, 1987 |
Maryland sand |
0.5 |
0.2 |
42.3 |
|
Mississippi loam |
0.7 |
1.2 |
176.5 |
|
Iowa sandy loam |
2.9 |
4.6 |
155 |
|
Mean K-values |
|
2.5 |
128.5 |
|
Speyer 2.1 |
0.4 |
1.2 |
340.4 |
Reischmann, 1997 |
Collombey |
0.8 |
1.6 |
210.9 |
|
Les Evouettes |
2.1 |
7.1 |
335.6 |
|
Vetroz |
4.4 |
13 |
296.3 |
|
Illarsaz |
19.3 |
51.5 |
266.4 |
|
Mean K-values |
|
14.9 |
290 |
|
Overall Mean K-values |
|
9.4 |
218.1556 |
|
The study by Spare (1987) indicates that benoxacor is adsorbed relatively weakly to sterile soil, whilst the more recent study performed by Reischmann (1997) indicates greater adsorption potential for non-sterilised soil. As a worst-case, it is proposed to use the overall mean value of 218 L/kg in the Chemical Safety Assessment. This means that the substance falls within the classification of moderately mobile, as defined by PSD (2000). This designation does not take account of the fast soil degradation rate of benoxacor.
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.
