slag, copper smelting

Endpoint summary

Description of key information

Complex metal containing substance

Water solubility of the substance is poor (for metal constituents)

Several high quality studies demonstrate no negative effects .An LDs 50 of > 2000 mg/kg bw were assessed. Copper slag is considered non toxic via oral, dermal and inhalation route.

Classification based on rules for mixtures

In vitro bio-accessability in artificial biological fluids ( gastric and sweat)

Key value for chemical safety assessment

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

discriminating dose

Additional information

The copper slag is a complex metal containing substance (UVCB). It mainly contains iron silicate and silicates of aluminum and calcium. Traces of metals exist in metal, mineral form or included in silicate phases.

Substance is used in massive, granular or powder form with varying particle size distribution (IUCLID section 4.5). Routes for exposure to consider are therefore oral and inhalation.

Copper slag is inorganic solid poorly soluble in water. It is not likely to penetrate though organic media. Absorption of copper slag through the skin is therefore considered to be of less significance than absorption through the respiratory and gastrointestinal routes

 The following test data were obtained:

-         The acute oral effects - LD₅₀ > 2000 mg/kg ( 3 studies)

- The acute dermal effects - LD₅₀ > 2000 mg/kg ( 2 studies)

These data are used for classification.

Additionally classification was derivedbased on rules for mixtures:

-         The calculated Oral Acute toxicity estimate of the mixture is > 2000 mg/kg

-         The calculated Inhalation Acute toxicity estimate of the mixture is > 5mg/l

Results from calculated classification are further supported (WoE) by consideration of physical chemical properties of the UVCB substance.

Chemistry and mineralogy of the slag (see IUCLID section 4.23 chemical and mineralogical characterization) were taken into account.

Water solubility (IUCLID section 4.8) and Sequential dissolutions (IUCLID 4.23 Chemical assays) furthermore confirmed species present and their solubility behavior.

 

Justification for classification or non-classification

Acute oral classification

 

Based on the available acute oral toxicity data ( i.e LD50> 2000 mg/kg ) and calculated Oral Acute toxicity estimate ( ATE >2000 mg/kg ) copper slag is not classified as hazardous for acute toxicity by the oral route.

 

Acute inhalation classification

 

No test data on acute inhalation toxicity are available. The calculated Inhalation Acute toxicity estimate of the mixture is > 5mg/l thus copper slag is not classified as hazardous for acute toxicity by the inhalation route.

 

Acute dermal classification

 

Consideration of available acute dermal toxicity data (i.e. LD₅₀>2000 mg/kg) leads to the conclusion that copper slag does not require classification for acute lethal effects.

Copper slag is an inorganic solid poorly soluble in water. It is not likely to penetrate through skin in any significant quantity and so would therefore not cause any toxic effects following dermal exposure. Furthermore, negligible metal release in in-vitro bio-accessibility test in artificial sweat fluid was observed (0.021 to 0.036 µg Ni/cm2/week)