Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The content of the test item was determined by a validated method of high performance liquid chromatography with DAD detection [SPR/C/216].
In the definitive test from each test concentration and the control the samples of fresh solutions were taken at exposure initiation and the samples of old solutions were taken at exposure termination (i.e. pooled replicates) [SOP/W/83].

Details on test solutions:

An undiluted filtrate of a loading of 100 mg/L and its 2-, 4-, 8- and 16-fold dilutions with the test medium plus the control were tested.
In the definitive test 125.09 mg of the test item was weighed into a glass flask (analytical balance SBC22, Scaltec) [SOP/W/7] and quantitatively transferred into a glass flask by multiple washing with test medium in a total volume of 1250 mL. The mixture was heterogeneous with visible not dissolved
parts of the test item. Therefore, the mixture was heated for 2 hours at 50oC in a water bath and then sonicated for 30 min (ultrasonic bath, Sonic-10, Polsonic [SOP/W/78]). The non-dissolved part of the mixture was separated by filtration thorough a conditioned nitrocellulose membrane filter (filter type HAWG, 0.45 Xm pores, Millipore) [SOP/W/37]. The filtrate was a homogeneous and transparent solution and was used as the highest test concentration. The lower test concentrations were prepared by sequential dilutions with the test medium in a ratio 1 : 1, volume per volume (as given in Table 1). The generated solutions were treatments named: an undiluted filtrate of a loading of 100 mg/L and its 2-fold dilution, 4-fold dilution, 8-fold dilution and 16-fold dilution.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus (< 24 h old at test initiation), not first brood progeny, range of parent daphnid age: 21 – 25 days, neonates collected from
laboratory culture in the Institute of Industrial Organic Chemistry Branch Pszczyna, Department of Ecotoxicology, Laboratory of Aquatic Toxicology.

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Test temperature:

21.2 – 21.7°C

pH:

7.69 - 7.97

Dissolved oxygen:

8.5 - 9.2

Nominal and measured concentrations:

nominal [mg/L] - measured [average, mg/L]
control - 0.000
0.5 - 0.429
1.0 - 0.840
10.0 - 8.063

Details on test conditions:

daily cycle: 16 h light : 8 h darkness without illumination by fluorescent light source, no feeding, no aeration.

Reference substance (positive control):

no

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.53 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Results with reference substance (positive control):

EC50 = 0.63 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

3.53 mg/L