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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.

Diss Factsheets

Administrative data

Hazard for aquatic organisms

Hazard for air

Hazard for terrestrial organisms

Hazard for predators

Additional information

Conclusion on classification

Two study reports (rated as Klimisch 1) on aquatic organisms are available covering two trophic levels: a primary producer (freshwater algae, represented by the model species Pseudokirchneriella subcapitata) and a primary consumer (aquatic invertebrates, represented by the model species Daphnia magna).


The freshwater algae P. subcapitata was exposed to N2-Isobutyryl-5’-O-(4,4’-Dimethoxytrityl)-2’-deoxyguanosine for 72 hours in a GLP toxicity study (OECD 201) at a limit concentration of 4.92 mg/L (measured, limit of water solubility, loading 100 mg/L nominal). No effect on P. subcapitata was observed.


D. magna was exposed for 48 hours to N2-Isobutyryl-5’-O-(4,4’-Dimethoxytrityl)-2’-deoxyguanosine in a static short-term GLP toxicity study (OECD 202) at measured concentrations of 0.98, 1.98, 3.51, 5.35 and 8.87 mg/L (measured geom. mean). In this study a NOEC of 5.35 mg/L and an EC50 of 8.29 mg/L were derived. The test concentrations were evaluated analytically by HPLC-UV.


Considering that N2-Isobutyryl-5’-O-(4,4’-Dimethoxytrityl)-2’-deoxyguanosine is not readily biodegradable based on ThCO2 (Flach 2018), and the lowest effect value was determined to be > 1 mg/L and < 10 mg/L (EC50 = 8.29 mg/L N2-Isobutyryl-5’-O-(4,4’-Dimethoxytrityl)-2’-deoxyguanosine has to be classified as "Aquatic Chronic 2" (H411) following the provisions laid down in the CLP Regulation (Regulation (EC) No 1272/2008).