Sulfamethoxazole
Summary
Persistence. Sulfamethoxazole is potentially persistent.
Bioaccumulation. Sulfamethoxazole has low potential for bioaccumulation.
Toxicity. Sulfamethoxazole has very high chronic toxicity.
Risk. Good margin between occurrences in Swedish waters and concentration for effect. Low risk for selection of antibiotic resistant bacteria.
The data on hazard are based on previous environmental information on fass.se. According to Aspen Nordic, no environmental data are available (2026-07-08). The risk is based on a report by Goodpoint.
Sulfamethoxazole is included in the EU Groundwater Directive (2006/118/EC), for which a threshold value has been established.
Detailed information
Fass environmental information Bactrim
Fass environmental information for Bactrim (sulfamethoxazole, trimethoprim) from Roche (downloaded 2019-06-14).
Hazard
Persistence: "Biotic Degradation:
Ready biodegradability:
4% after 28 days of incubation BOD/ThOD (OECD 301 D)
13% after 28 days of incubation BOD/ThOD (OECD 301 D with co-metabolism)
Inherent biodegradability:
-10% after 28 days of incubation CO2/TOC (OECD 302 B)
13% after 28 days of incubation DOC (OECD 302 B)
0% after 28 days of incubation DOC (OECD 302 B).
Sulfamethoxazole is neither readily, nor inherently biodegradable. This justifies the phrase 'Sulfamethoxazole is potentially persistent.'"
Bioaccumulation: Log Kow 0.89 experimental, method unknown. Log Kow 0.48 QSAR. Sulfamethoxazole has low potential for bioaccumulation (log Kow < 4).
Toxicity: There are data for 3 trophic levels, most sensitive Cyanobacteria (Synechococcus leopoliensis) NOEC 96 h = 0.0059 mg/l (method not specified)".
Risk
PEC/PNEC is based on sales data in Sweden in year 2017. PEC/PNEC = 0.440 which gives the risk low.
Fass environmental information Eusaprim
Fass environmental information for sulfamethoxazole from Eusaprim (sulfamethoxazole, trimethoprim) from Aspen Nordic (retrieved on 2026-07-08).
Hazard
Persistence: No data.
Bioaccumulation: No data.
Toxicity: No data.
Risk
Risk of environmental impact of sulfamethoxazole cannot be excluded, due to the lack of environmental toxicity data.
Report Goodpoint
Good margin between occurrences in Swedish waters and concentration for effect. Low risk for selection of antibiotic resistant bacteria.
Pharmaceutial residues in the aquatic environment
Sulfamethoxazole has been detected in treated wastewater in Region Stockholm and in the aquatic environment elsewhere in Sweden.
EU water legislation
Sulfamethoxazole is included in the EU Groundwater Directive (2006/118/EC), for which a threshold value has been established.
In general
For antibiotics in general, it is recommended that these drugs are used as restrictively as possible without risking the patient's health.
References
- Fass.se för vårdpersonal.
- Goodpoint. Prioritering av läkemedel med miljörisk inom SLL. Stockholm: Goodpoint; 2016. Rapport LS 2016–0634.
- Provtagningar av läkemedelsrester i vatten, sediment och fisk för Region Stockholm.
- IVL Swedish Environmental Research Institute Ltd. Fick J, Lindberg RH, Kaj L, Brorström-Lundén E. Results from the Swedish National Screening Programme 2010. Subreport 3, B 2014 Pharmaceuticals.
- IVL Swedish Environmental Research Institute Ltd Fick J, Lindberg RH, Fång J, Magnér J, Kaj L, Brorström-Lundén E. Screening 2014. Analysis of pharmaceuticals and hormones in samples from WWTPs and receiving waters. Rapport C 135.
- Hillis DG, Antunes P, Sibley PK, Klironomos JN, Solomon KR. Structural responses of Daucus carota root-organ cultures and the arbuscular mycorrhizal fungus, Glomus intraradices, to 12 pharmaceuticals. Chemosphere. 2008;73:344-52.
- Bengtsson-Palme J, Larsson DG. Concentrations of antibiotics predicted to select for resistant bacteria: Proposed limits for environmental regulation. Environ Int. 2016;86:140-9.
- DIRECTIVE 2006/118/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL.
Author: Health and Medical Care Administration, Region Stockholm