Propane-1,2-diyl dibenzoate

Endpoint summary

Description of key information

Key data is available for propylene glycol dibenzoate (PGDB). This data is supported by relevant information available from a structural analogue Dipropylene glycol dibenzoate (DPGDB). The justification for read across is provided as an attachment included in Section 13 of the IUCLID dossier.

 

Short-term toxicity to fish

Based on the prediction results, propylene glycol dibenzoate was predicted to have a fish LC₅₀ of 3.7 mg/L after 96 hours exposure (ester class toxicity) (US EPA, 2012; Klimisch Score = 2).

 

The 96 h LC₅₀ value for DPGDB with fathead minnow was determined 3.7 mg/L. The "no-observed effect concentration" (NOEC) for DPGDB with fathead minnow was determined to be 1.2 mg/L (Huntingdon Life Sciences, 2000a; Klimisch score = 1).

 

The 96 h LC₅₀ value for DPGDB with rainbow trout was >3.0 mg/L. The "no-observed effect concentration" (NOEC) for DPGDB with rainbow trout was 3.0 mg/L (Huntingdon Life Sciences, 2000b; Klimisch score = 1).

 

These values are supported by the QSAR modelling (US EPA, 2009; Klimisch score = 2) with a 96-hour LC₅₀ value of 3.94 mg/L for DPGDB.

 

Long term toxicity to fish

A Guideline OECD 210 fish early-life stage toxicity study has been proposed for the structural analogue dipropylene glycol dibenzoate (DPGDB) and will be read across to once the study results are available.

 

Short-term toxicity to aquatic invertebrates

Propylene glycol dibenzoate is predicted to have LC₅₀’s of 4.325 mg/L (baseline toxicity) and 6.387 mg/L (Ester class) after 48 hours exposure to Daphnid (US EPA, 2012; Klimisch score = 2).

 

In an acute Daphnia Immobilisation GLP study conducted according to EC, OECD, and US EPA test guidelines (Huntingdon Life Sciences, 2001a; Klimisch score = 1), the 48 hour EL₅₀ (immobilisation value with Daphnia Magna) for dipropylene glycol dibenzoate was determined to be 19.3 mg/L. The "no-observed effect loading rate" (NOELR) was 2.2 mg/L. 

 

Long-term toxicity to aquatic invertebrates

There are no key data available for propylene glycol dibenzoate (PGDB). Data available from a structural analogue Dipropylene glycol dibenzoate (DPGDB) has been used to read-across to PGDB to fill this requirement. The justification for read across is presented as an attachment included in Section 13 of the IUCLID dossier.

In a 21 -day Daphnia reproduction GLP study conducted according to OECD 211 a NOEC (reproduction and growth) of 2.2 mg/l (based on the measured geometric mean) was reported (Smithers Viscient; Klimisch score = 1).

 

Toxicity to aquatic algae and cyanobacteria

In a GLP, OECD Guideline 201 study in unicellular green alga Pseudokirchneriella subcapitata, the NOEC and 72 hr EC₅₀ growth rate for propylene glycol dibenzoate was determined to be 0.298 and 1.53 mg/L, respectively (Huntingdon Life Sciences, 2015a; Klimisch score = 1).

 

Propylene glycol dibenzoate was predicted to have LC₅₀’s of 6.243 mg/L (baseline toxicity) and 2.066 mg/L (Ester class) after 96 hours exposure to green algae (US EPA, 2012; Klimisch score = 2).

 

In a GLP algal growth inhibition conducted according to EC, OECD 201, and US EPA test guidelines, the EL₅₀ (Area under the curve 72 h) for dipropylene glycol dibenzoate was 1.1 mg/L and the EL₅₀ (Growth rate 0 - 72 h) was 4.9 mg/L. The corresponding "no-observed effect loading rates" (NOELR) were 0.22 and 1.0 mg/L, respectively. The EL₅₀ (Area under the curve 96 h) was 0.95 mg/L and the EL₅₀ (Growth rate 0 - 96 h) was 3.6 mg/L. A NOELR could not be obtained for Area under the curve 96 h, the NOELR for growth rate was 0.46 mg/L (Huntingdon Life Sciences, 2001b; Klimisch score = 1). 

 

Toxicity to microorganisms

A GLP, OECD Guideline 209 study activated sludge respiratory inhibition test was performed with propylene glycol dibenzoate. The EC₅₀ was found to be >1000 mg/L and NOEC was determined to be 100 mg/L (Huntingdon Life Sciences, 2014d; Klimisch score = 1).

 

Two studies conducted according to international guidelines and in compliance with GLP, are available for DPGDB. The activated sludge respiration inhibition test demonstrated a NOEC ≥ 100 mg/L, the highest concentration tested (Huntingdon Life Sciences, 1998d; Klimisch score = 1). The assay on growth of the bacteria Pseudomonas putida demonstrated a NOEC ≥ 10 mg/L (Safepharm Laboratories Ltd.,1998a, Klimisch score = 1).