Pitch, coal tar, high-temp.

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

3.6 mg/L

Assessment factor:

10

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

0.84 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.366 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.01 mg/kg soil dw

Assessment factor:

50

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

0.28 mg/kg food

Assessment factor:

30

Additional information

Pitch, coal tar, high temp., is not considered to be an environmentally hazardous substance due to its inert inherent properties: because of its poor water-solubility and its complex high-molecular aromatic structure, it can be neither biodegraded nor bioaccumulated. Coal-tar pitch failed to show acute and chronic aquatic toxicity.

Daphnia and alga gave no evidence of chronic adverse effects up to a loading of 100 mg/L. Long-term studies in fish are not available. However, they are not supposed to generate chronic toxic effects that are relevant for classification. Furthermore, the classification proposal outlined below will include the aspect of chronic hazard.

Phototoxic effects produced by certain PAHs under the influence of sun/UV-light can be waived by way of a weight-of-evidence approach, namely by comparing water solubility and photo-toxicity data of critical key components of pitch.

Emissions from pitch that may arise during processing and uses consist of polycyclic aromatic hydrocarbons (PAH) that may constitute a hazard for men and environment. For the purpose of risk assessment, benzo(a)pyrene [BaP], one of the best characterised key components, has been chosen as marker substance for deriving PNEC values (see above).

PNECs derived for BaP are converted to PNECs for total coal tar pitch taking into account the total PAH content of coal tar pitch [see above under 'Introductory Remarks' (CSR Sect. 7.6.)].To compensate for additional aquatic toxicity from components in coal tar pitch other than BaP, a factor of 1/5 is applied on respective BaP PNECs. The resulting PNECs for total pitch, coal tar, high temp., are presented above.

Conclusion on classification

Because pitch is a UVCB substance, it is very difficult to classify it on the basis of the individual components. In addition, not all the components can be analysed when diluted in water. The composition in the water phase will not be the same at different loadings. As recommended for oil products and products such as creosote in the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (OECD, 2000), the water-accommodated fraction (WAF) approach is considered most appropriate to classify pitch. The classification criteria are applied to the loading rate.

Pitch, coal tar, high temp., produced no acute aquatic toxicity under standard test conditions in fish (OECD TG 203), in daphnia (OECD TG 202), and in algae (OECD TG 201). The effective loadings, EL50/LL50 values, were consistently higher than 100 mg/L. Based on weight of evidence, there is no concern over PAH-induced acute photo-toxicity. Furthermore, pitch has no bioaccumulation potential.

Hence, based on experimental evidence and weight of evidence, the pitch material requires no classification for environmental hazards in accordance to Directive (EU) 67/548/EEC. For precautionary reasons, taking into account that pitch may be a potential source of PAHs released into the environment, the labelling with R 53 is proposed.

Also in accordance to Regulation (EC) No 1272/2008, there is no need to classify pitch for acute toxicity. It is recommendable to classify pitch for long-term aspects as a potential source of environmental release of PAHs, which may be a cause of concern. This precautionary principle is covered by the “safety net” classification (Category: Chronic 4) [CLP Directive 1272/2008, 2nd ATP: EU Regul. 286/2011, 4.1.2.6, Table 4.1.0], hence H413 Chronic 4 is proposed.