Butyraldehyde

Endpoint summary

Description of key information

 

Butyraldehyde has been tested for acute aquatic toxicity in fish, daphnia, alga and bacteria as well as in various protozoa.

 

 

Table: Compilation of aquatic toxicity data

 

Strain	Guideline	Toxicity value	Source	Evaluation
6.1.1  Fish (short-term)
Pimephales promelas (Fathead minnow)	EPA-660/3-75-009	LC50(96h) = 25.8 mg/L	Curtis and Ward 1981	Rel 2
Leuciscus idus (Golden orfe)	DEV, part L15 (draft)	LC50(48h) = 57 mg/L	Juhnke and Lüdemann 1978	Rel. 2
Leuciscus idus (Golden orfe)	DEV, part L15 (draft)	LC50(48h) = 114 mg/L	Juhnke and Lüdemann 1978	Rel. 2
Leuciscus idus (Golden orfe)	DIN 38412 part 15	LC0(48h) =<50 mg/L (Toxicity Threshold)	Wellens 1977 (Hoechst)	Rel 4 (abstract)
Leuciscus idus (Golden orfe)	DIN 38412 part 15	LC0(48h) = 18 mg/L LC50(48h) = 24 mg/L	Scheubel and Pommer 1980 (Hüls)	Rel 3 (48 h, emulsifier, substance identity questionable)
6.1.2  Fish (long-term)
Poecilia reticulata (guppy)	No data (OECD 204), semi-static	LC50(14d) = 13.7 mg/L	Deneer JW, Seinen W, Hermens JLM (1988)	Rel 2
6.1.3  Invertebrates (short-term)
Daphnia magna	OECD 202	EC50 (48h)= 20mg/L (18 to 22 confidence level)	J Bradshaw 2023	Rel 1
Daphnia magna	DIN 38412, part 11	EC0(24h) = 100 mg/L EC50(24h) = 195 mg/L	Bringmann and Kühn 1982	Rel 2
Daphnia magna	Similar to DIN 38412, part 11	EC0(24h) = 120 mg/L EC50(24h) = 340 mg/L	Bringmann and Kühn 1982	Rel 2
Aedes aegyptilarvae (mosquito)	No data	LC50(4h) = ~1600 mg/L	Kramer et al. 1983	Rel 3 (only 4 h, not validated system, poor documentation)
6.1.5  Alga/Cyanaobacteria
Raphidocelis subcapitata	OECD 201	ErC50 (72h)= 7.3 mg/L; 95% confidence limits 5.8 to 9.4 mg/L NOEC (72h)= 0.89 mg/L	J Bradshaw 2023	Rel 1
Scenedesmus quadricauda	No data	EC0(8d) = 83 mg/L (MIC)	Bringmann and Kühn 1977/1978a	Rel 3 (methodological deficiencies)
Mixed population with mainlyScenedesmussp.	DEV L12 (1971)	EC10(24h) = 110 mg/L EC50(24h) = 380 mg/L	Krebs 1991	Rel 3 (methodological deficiencies)
Microcystis aeroginosa	No data	EC0(8d) = 19 mg/L (MIC)	Bringmann and Kühn 1978b	Rel 3 (methodological deficiencies)
6.1.7  Microorganisms
·        Bacteria
Pseudomonas putida	DIN 38412, part 8	EC0(16h) = 100 mg/L (MIC)	Bringmann and Kühn 1977/1980	Rel 2
Pseudomonas fluorescence	DEV L8	EC0(16h) = 100 mg/L (MIC)	Bringmann 1973	Rel 4 (Secondary source)
Activated sludge, domestic	ETAD Fermentation Tube Assay	EC0/EC10(24h) = 150 mg/L (MIC)	Wellens 1777 (Hoechst)	Rel 4 (abstract)
Photobacterium phosphoreum	Microtox test	EC50(15min) = 106.7 mg/L EC50(5min) = 153.6 mg/L	Chou and Hee	Rel 2
Photobacterium phosphoreum	Microtox test	EC50(5min) = 16.4 mg/L	Curtis et al. 1982	Rel 4 (Secondary source)
·        Protozoans
Uronema parduzci	No data	EC0(20h) = 98 mg/L (MIC)	Bringmann and Kühn 1980/1981	Rel 2
Chilomonas paramaecium	No data	EC0(48h) = 44 mg/L (MIC)	Bringmann and Kühn 1980/1981	Rel 2
Entosiphon sulcatum	No data	EC0(72h) = 4.2 mg/L (MIC)	Bringmann and Kühn 1978/1980/1981	Rel 2
·        Heterogeneous population
Mixed heterotrophic population	DEV L12 (1971)	EC10(24h) = 30 mg/L EC50(24h) = 60 mg/L	Krebs 1991	Rel 4 (Secondary source)

MIC = minimum inhibitory concentration

Discussion of data

A series of five acute and one 14 day fish toxicity study were performed with butyraldehyde. The acute fish toxicity studies were performed over 48 or 96 hours, the LC50 values for the 48 hour exposure period ranged between 24 and 114 mg/L and the 96 hour LC50 was 25.8 mg/L. The 14 day study, conducted with the guppy (Poecilia reticulata) gave an LC50 value of 13.7 mg/L.

 

Three 24 hour acute toxicity studies were performed with Daphnia magna and one 4 hour toxicity study was performed with Aedes aegyptilarvae (mosquito). Among these studies one study was performed following the OECD 201  and the rest of the studies were non-guideline studies. The EC50 value derived from the J Bradshaw 2023 (OECD 201) study was 20mg/L (18 to 22 confidence level). The rest of the studies were considered to be supportive.

 

Three alga/cyanobacteria studies were performed with butyraldehyde, where except the J Bradshaw 2023, the rests were non-guideline studies. Therefore, the non-guideline studies were considered to be used supportive studies. From the OECD 201 J Bradshaw 2023 study, an ErC50 (72h)= 7.3 mg/L; 95% confidence limits 5.8 to 9.4 mg/L and NOEC (72h)= 0.89 mg/L was obtained.

 

A series of bacteria studies were performed, EC0 values of 100 mg/L were obtained with Pseudomonas putida and Pseudomonas fluorescence. In addition microtox test, using Photobacterium phosphoreumgave 5 minute EC50 values of 16.4 and 153.6 mg/L and a 15 minute EC50 of 106.7 mg/L.

 

Three protozoan species were tested, Uronema parduzci 20 hour EC0 of 98 mg/L, Chilomonas paramecium48 hour EC0 44 mg/L and Entosiphon sulcatum72 hour EC0 of 4.2 mg/L. A study conducted on a mixed heterotrophic population provided a 24 hour EC50 of 60 mg/L.

 

It is recognized that the majority of the studies do not meet the current criteria for standard methods, typically the studies were performed over shorter durations, analysis was not performed and non-standard test species were used. Therefore, the newly obtained OECD 201 and 202 studies has been considered to conclude on the n- Butyraldehyde.  

There was hazard observed in Raphidocelis subcapitata and the lowest appropriate ErC50 (72h)= 7.3 mg/L; 95% confidence limits 5.8 to 9.4 mg/L NOEC (72h)= 0.89 mg/L were considered to  be used to derive aquatic PNEC.

 

Based on the data set provided the key endpoint for setting the PNEC STP is the 16 hour EC₀value of 100 mg/L from the study with Pseudomonas putida.