Lubricating oils, used, distd.

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD 23:2019

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

not specified

Details on sampling:

The sample is not soluble in water. A stock Water Accommodated Fraction (WAF) was prepared, then diluted to get the other tested doses. This is acceptable according to point 149 of § 7.9.2.4 “Preparing water-accommodated fractions (WAFs)” of the guidelines OECD 23:2019 – “Guidance document on aquatic toxicity testing of difficult substances and mixtures”. In fact, in the present study it was not be possible to prepare each WAF individually. This was due to the limitations of weighing small amounts of UVCB and the large test solution volumes required. An ASTM Type III water was used for elution and dilutions. The test medium was prepared adding the above salts to the WAF and its dilutions

Vehicle:

no

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Test type:

not specified

Water media type:

not specified

Limit test:

no

Details on test conditions:

As agreed with the Sponsor, the algae were exposed to serial dilutions obtained from a stock Water Accommodated Fraction (WAF) according to OECD 23:2019, with a loading rate (nominal concentration) of 100 mg/L.
The algal biomass was determined at 24, 48 and 72 hours and compared with the values of the blank to evaluate the growth inhibition.
The results are processed and analysed to assess the ErL50 and NOEC values of the sample at 72 h.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

other: NOEL

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Details on results:

Acute toxicity
At the end of the test, the sample has no influence on the algae growth rate compared to the control at any dose. Therefore, we can say that the ErC50 at 72h (concentration at which we will have %Ir ≥ 50%) is greater than 100 mg/L, which is the maximum tested nominal concentration of the WAF.
Chronic toxicity
Since no tested dose has a statistically significant effect on the growth of algae, we can consider that the NOEC (No Observed Effect Concentration, %Ir = 0%) is also greater than 100 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The algae ErL50 and NOEL at 72h are greater than 100 mg/L, which is the maximum tested nominal concentration of the WAF.

Description of key information

The substance has a ErL50 >100 mg/L.

The substance has a NOEC >100 mg/L.