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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 203-157-5 | CAS number: 103-90-2
Toxicity to aquatic algae and cyanobacteria
Administrative data
Link to relevant study record(s)
Description of key information
The effect of test item paracetamol, CAS No. 103-90-2 was studied on the growth of fresh water green algaChlorella vulgaris.The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 6.25mg/l, 12.5mg/l, 25mg/l, 50mg/l, 100mg/l and 200mg/l. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 112.666mg/l.Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance Paracetamol does not exhibit toxicity to aquatic algae (Chlorella vulgaris).
Key value for chemical safety assessment
- EC50 for freshwater algae:
- 112.666 mg/L
- EC10 or NOEC for freshwater algae:
- 22 mg/L
Additional information
The effect of test substance Paracetamol, CAS No. 103-90-2 was studied on the growth of fresh water
green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga growth inhibition test.The green alga (Chlorella vulgaris) was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 112.666 mg/L.
Based on the study conducted using the prediction model of QSAR, the median effective concentration (EC50) was estimated to be 169 mg/L.
In another study conducted by Wiegel et.al (Arzneistoffe in Elbe und Saale; VII, 123 und Anhang; 2003),the 72hr EC50 to be 134mg/l in Pseudokirchnerella subcapitata on the basis of growth rate effect.
Also the data from the report of Ministry of the Environment, Japan and J-CHECK database, indicates the median effective concentration (EC50) and the
No-observable-effect-concentration (NOEC) in a 72 hours study on the basis of growth rate and AUG effect was reported as 150 to >460 mg/L and 22.0 to 46.0 mg/L .
Based on the above studies available for the substance Paracetamol ,the EC50 is ranging from 112.666 to >460 mg/L and NOEC is ranging from 22.0 to 46.0 mg/L in aquatic algae in a 72 hour study on the basis of various effects such as growth rate effect and AUG effect. Thus, it is concluded that Paracetamol does not exhibit toxicity to aquatic algae i.e.it is non-hazardous to the aquatic environment for the purpose of classification of the substance as per the new CLP guidelines.
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.
