Ladle skimming slag, Ladle furnace refining, slag, Ferrous slag

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not reported

Analytical monitoring:

not required

Details on sampling:

weighted before start of experiment

Vehicle:

no

Details on preparation and application of test substrate:

The sample was prepared as a leachate with L/S 4/1 (1000 ml of deionized sterile water to 250g of solid material) by shaking at 30 rpm for 20 h, followed by decantation for 1h in order to obtain a concentration of 100 %.
The 100 % stock solution was mixed with soil equivalent to 100 % solution to obtain the following final test concentrations: 2.08 %, 4.16 %, 8.33 %, 16.66 % and 33.33 % L/kg. The soil (in total 750 g) was placed in 2 L plastic flasks.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Each 10 healthy annelids were given in each test containers and acclimatised in humid soil under test temperature and photoperiod conditions for 24 h.

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Post exposure observation period:

not required

Test temperature:

According to OECD guideline 207

pH:

presumably basic

Details on test conditions:

Four replicates were made for each treatment. Mortality, mobility and any other irregularities were evaluated after 7 and 14 d after the beginning of the incubation.

Nominal and measured concentrations:

nominal

Reference substance (positive control):

not specified

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

ca. 83 other: g/kg soil

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mortality and behaviour

Results with reference substance (positive control):

Positive control not reported but GLP and comparison with crushed natural stone (LC50 83g/kg soil)

Reported statistics and error estimates:

Fisher´s Exact Proof

Validity criteria fulfilled:

yes

Conclusions:

SMS: OECD 207, Eisenia fetida: 14 d-LC50 approximately 83 g/kg/soil (not neutralized, nominal)

Executive summary:

To check the toxicity of slags to earthworms, slags, steelmaking (SMS) were tested on the annelid Eisenia fetida according to OECD TG 207. Tests were performed using a L/S (liquid/solid) of 4/1 leachate (0.25 kg of slag/L of leaching medium). The leachates were neither neutralized nor filtered. The leachates were mixed with artifical soil to obtain 5 concentrations 2.08 %, 4.16 %, 8.33 %, 16.66 % and 33.33 % L/kg soil.

Basic leachates of SMS are not toxic to Eisenia fetida in an acute earth worm test according to OECD TG 207. The 14 d-LC₅₀ is approximately 83 g/L (nominal).

As verms tolerate only a limited pH range, these experiments indicate some pH influence. However, the results confirm that slags exert no acute toxicity to earthworms.

Description of key information

Aquatic toxicity studies are not available for Slag, pig iron ladle refining, non-granulated, water-cooled. Read-across to the assessment entity (analogue approach) to slags, steelmaking is applied for the assessment of Slag, Pig Iron ladle refining, non-granulated, water-cooled since the solved metal ion concentrations determine its fate and toxicity in the environment. Based on result of a leaching experiment performed with the target substance (i.e., Slag, pig iron ladle refining, non-granulated, water-cooled) and the source substance (i.e., slags steelmaking) solved metal ion concentrations of the target substance are similar to the solved metal concentrations of the source substance. Read-across is fully justified and discussed in detail in the RAAF document attached on IUCLID section 13.

ABS: Eisenia fetida OECD 207: 14 d-LC0 = 100 g/kg (highest concentration tested) ABS: Eisenia fetida ISO 11268-1: 14 d-LC50 = 770 g/kg (highest concentration tested)

Additional information

In an earthworm acute toxicity test performed according to OECD 207 and GLP, powdered air-cooled blast furnace slag (ABS) did not affect survival or body fresh weight of the earthworm Eisenia fetida during 2 weeks incubation in soil with a maximum concentration of 100 g of the slag per kg of artificial OECD soil (highest concentration tested, NERI 2008).

The effects of slags on earthworms were measured in a 14 d test according to ISO 11268-1 (Effects of Pollutants on Earthworms. 1. Determination of Acute Toxicity Using Artificial Soil Substrate). ABS was not toxic against Eisenia fetida within 14 days. The LC50 was 770 g/kg (highest concentration tested, LECES 1999).