Dipropoxymethane

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Remarks:

ECOSAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well known model generally regarded as reliable. Cited as source of information in REACH guidance on information requirements and chemical safety assessment

Justification for type of information:

1. SOFTWARE
ECOSAR

2. MODEL (incl. version number)
(v2.0)

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
CCCOCOCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
[[Explain how the model fulfils the OECD principles for (Q)SAR model validation. Consider attaching the QMRF and/or QPRF or providing a link]
- Defined endpoint:
- Unambiguous algorithm:
- Defined domain of applicability:
- Appropriate measures of goodness-of-fit and robustness and predictivity:
- Mechanistic interpretation:

5. APPLICABILITY DOMAIN
See attached justification files

6. ADEQUACY OF THE RESULT
The 96-h LC50 value for fish is predicted to be 175 mg/L. There is no consequence for classification due to this effect value, as algae remains the most sensitive species to Propylal (i.e. shows the lowest ErC50 > 15.8 mg/L, OECD TG 201, GLP).

Qualifier:

no guideline followed

Principles of method if other than guideline:

QSAR method based on chemical class principle: ECOSAR (v2.0) from EPISUITE (US EPA)

GLP compliance:

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

175 mg/L

Nominal / measured:

estimated

Conc. based on:

not specified

Basis for effect:

not specified

Validity criteria fulfilled:

not applicable

Conclusions:

The increasing toxic effect with increasing length of the chain alkane (i.e. the toxicity level is Ethylal< Propylal < Butylal) is found for all three trophic levels (fish, invertebrates and algae) in experimental studies and ECOSAR predicted results. Therefore, Propylal is expected to be more toxic to fish than Ethylal. It means the effect value from the short-term toxicity to fish study on Ethylal cannot be used for read-across to Propylal, since Propylal is expected to be more toxic. No experimental study is available on Butylal, which is expected to be significantly more toxic than Propylal. Based on this information, ECOSAR is deemed more appropriate for this endpoint than the read-across approach. Therefore, the 96-h LC50 value of Propylal to fish is predicted to be 175 mg/L according to ECOSAR (v2.0). The QMRF and QPRF are attached to this endpoint of the dossier.

Executive summary:

A short-term toxicity study to fish is available for Ethylal (source substance 1), but not for Butylal (source substance 2). ECOSAR results show an increasing toxic effect trend with increasing length of the chain alkane (from C5 to C9) for all three trophic levels (fish, invertebrates and algae). The trend is also found in the available experimental studies on aquatic invertebrates. The 48-h E(L)C50 values for daphnia were determined to be 468 (publication, not GLP), > 100 (OECD TG 202, GLP) and > 28.7 mg/L (OECD TG 202, GLP) for Ethylal, Propylal and Butylal, respectively. Experimental studies are available for the toxicity to algae and cyanobacteria endpoint for Propylal and Butylal, but not for Ethylal. Therefore, it is difficult to study the trend of toxicity levels of these three substances via the available studies. But Butylal (72h-ErC50 > 1.3 mg/L; 72h-NOErC < 1.3 mg/; OECD TG 201, GLP) shows higher toxicity than Propylal (72h-ErC50 > 15.8 mg/L; 72h-NOErC = 1.09 mg/; OECD TG 201, GLP), which is in line with the trend observed for the other trophic levels. ECOSAR was used for Ethylal, Propylal (target substance) and Butylal, and predicted the 96h-LC50 values for fish are 1050, 175 and 27.8 mg/L, respectively.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

175 mg/L