Detaljerad miljöinformation

Environmental Risk Classification

Predicted Environmental Concentration (PEC)

PEC is calculated according to the following formula:

PEC (μg/L) = (A*10⁹*(100-R))/(365*P*V*D*100) = 1.37*10^-6 * A * (100 - R) = 1.37*10^-6 * 6.68 kg * 100 = 0.00091 μg/L = 0.91 ng/L

Where:

A = 6.6826 dexametasone (sum of 4.3866 kg dexametasone and 3.0198 kg dexametasone natriumphosphate, equaling 2.296 kg dexamethasone) (total sold amount API in Sweden year 2021, data from IQVIA).

R = 0 % removal rate (due to loss by adsorption to sludge particles, by volatilization, hydrolysis or biodegradation) = 0, if no data is available.

P = number of inhabitants in Sweden = 10 * 10⁶

V (L/day) = volume of wastewater per capita and day = 200 (ECHA default) (ECHA 2008)

D = factor for dilution of waste water by surface water flow = 10 (ECHA default) (ECHA 2008)

Predicted No Effect Concentration (PNEC)

Ecotoxicological studies

Algae (Pseudokirchneriella subcapitata) (ISO 8692, 1987) (Della Greca et al. 2004):

ErC50 72 h (growth inhibition) > 100.0 mg/L

Crustacean (Daphnia magna):

Acute toxicity

EC50 24 h (immobilisation) > 100.0 mg/L (OECD 202) (Ciba-Geigy Project No. 830166)

Other ecotoxicity data:

Bacterial Respiration Inhibition:

EC₅₀ 3 h > 320 mg/L (Inhibition of Oxygen Consumption by activated sludge, 87/302/EEC, Part C) (ECOTOXICOLOGY Report N 139 05)

PNEC derivation:

No PNEC can be calculated since there is not sufficient information on environmental toxicity available

Environmental risk classification (PEC/PNEC ratio)

Calculation of a risk ratio is not possible, as there is not sufficient environmental toxicity data available. Therefore, the following phrase is used: "Risk of environmental impact of dexametasone cannot be excluded, since there is not sufficient ecotoxicity data available."

Degradation

Biotic degradation

Ready degradability:

0 %, not readily biodegradable (OECD301E) (Ciba-Geigy, Project No. 83 01 65)

Justification of chosen degradation phrase:

As dexamethasone does not fulfil the criteria for ready biodegradability, the following phrase is chosen for degradation potential: ‘Dexamethasone is potentially persistent.’

Bioaccumulation

Partitioning coefficient:

logK_ow = 1.83 (method unknown) (Alcon Technical Report No. 090:38560:0796)

Justification of chosen bioaccumulation phrase:

As log K_ow < 4, the following statement is used for Dexamethasone: ‘Dexmethasone has low potential for bioaccumulation.’ 

Excretion (metabolism)

Dexamethasone is eliminated from plasma with a half-life of 2.4-3.5 hours. The mean plasma clearance is 245 mL/min.

Within 24 hours 64% of a radioactive dose of 0.5-1.5 mg dexamethasone is excreted in the urine. Up to 36% of the dose is recovered in the urine in the form of the principal metabolite, 6β-hydroxyldexamethasone, and about 2% of the dose is found in the form of unchanged dexamethasone (Millicorten® Basic Drug Information, CIBA, 1994).

References

1. ECHA 2008, European Chemicals Agency. 2008 Guidance on information requirements and chemical safety assessment. http://guidance.echa.europa.eu/docs/guidance_document/information_requirements_en.htm

2. Della Greca et al. 2004. Toxicity of prednisolone, dexamethason and their photochemical derivatives on aquatic organisms. Chemosphere 54, p. 629-637.

3. Ciba-Geigy, Project No. 830166, Final report: 26.5.1983 (report / full reference not available)

4. ECOTOXICOLOGY Report N 139 05 (report / full reference not available, including date)

5. Ciba-Geigy, Project No. 83 01 65, Final report: 28.4.1983 (report / full reference not available)

6. Alcon Technical Report No. 090:38560:0796 (report / full reference not available, including date)

7. Millicorten® Basic Drug Information, CIBA, October 19^th, 1994.

8. Laboratories Limited, March 2009.