Tar, brown-coal, low-temp.

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.294 mg/m³

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

150

Modified dose descriptor starting point:

LOAEC

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.08 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

600

Modified dose descriptor starting point:

LOAEL

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

Additional information - workers

Exposure pattern	Route	Descriptors	DNEL/DMEL (appropriate unit)	Most sensitive endpoint	Justification
Acute - systemic effects	dermal (mg/kg bw /day)
	Inhalation (mg/m^3)
Acute - local effects	Dermal (mg/cm^2)
	Inhalation (mg/m^3)
Long-term - systemic effects	Dermal (mg/kg bw /day)	Corr LOAEL = 50 mg/kg bw/d         HT25 0.016-0.038 mg BaP/kg bw/d	DNEL = 0.08  mg/kg bw/day           DMEL 1.28 – 3.04 ng BaP/kg bw/d	Liver and kidney damage, haematological alteration   Skin carcinoma, other skin tumors
	Inhalation (mg/m^3)	Corr LOAEC: 44.1 mg/m^3       HT25 14.39 – 35.67 μg BaP/m^3	DNEL = 0.294 mg/ m^3       DMEL 1.2 – 2.9 ng BaP/ m^3	Liver and kidney damage, haematological alteration   Lung tumors
Long-term – local effects	Dermal (mg/cm^2)
	Inhalation (mg/m^3)

Risk assessment of Tar, brown-coal, low temp., was performed, with chronic toxicity and carcinogenicity being the major health effects considered. The main source of uncertainty in this risk assessment represents the lack of specific data for Tar, brown-coal, low temp.For the test substance, both, threshold and non-threshold modes of action were assumed. Subsequently, quantitative and semi-quantitative risk assessments were performed and both, Derived No-Effect Level (DNEL) and Derived Minimal Effect Levels (DMELs) were derived. 

Concerning Derived No-Effect Level (DNEL) determination for non-carcinogenic effects, LOAEL of 50mg/kg bw/dbased on a subchronic study in rat exposed by oral gavage (VUOS, 2011) was used. The main health effects observed were liver and kidney toxicity, including structural and functional damage of the mentioned organs. Furthermore, irreversible alterations of hematologic parameters and atrophy of the genital organs in both sexes of tested animals were found.

Regarding carcinogenicity, within this risk assessment of Tar, brown-coal, low temp., due to the complex character of the test substance and a limited database available,the presence of its main contaminants - Polycyclic Aromatic Hydrocarbons (PAHs) and specifically Benzo(a)pyrene (BaP), was considered as an indicator of exposure to the Tar, brown-coal, low temp., using the same approach as in the EU Risk Assessment Report for Coal-Tar Pitch, high temperature (2008). However, compared to the Coal-Tar Pitch, high temperature, Tar, brown-coal, low temp., contains much lower levels of PAHs and specifically BaP. This fact must be kept in mind, when considering uncertainties with respect to this CSR. On the other hand, Tar, brown-coal, low temp., is classified as the Carcinogen 1A, mainly due to the presence of PAHs, so the primary aim of the risk reduction measures must be to minimize potential contact with the substance as much as possible.

As the primary indicator of PAHs, BaP, one of the most toxic PAHs and known carcinogen and mutagen, was considered. Thus, DMELs within this CSR are derived from data on BaP.

Although there is a lack of knowledge on health effects of other chemical constituents of Tar, brown-coal, low temp., it is very likely thatthe limitation of the risks for cancer will automatically reduce the risk for any other possible health effects. 

For DMELs calculations, dose descriptors – T25 – used in this assessment were taken from theRestriction Report – Proposal for a Restriction, Annex XV, byFederal Institute for Occupational Safety and Health (,, 2010), focused on the restriction of selected PAHs in consumer products. Although besides T25, BMD10 and BMDL10 were calculated in the mentioned report, T25 were chosen, because these dose descriptors could be derived directly from the studies without necessity of route-to-route extrapolation. For BMD10 and BMDL10, route-to-route extrapolation would be needed (no adequate inhalation studies) and consequently, uncertainty in this risk assessment would further increase.

Two different approaches were used for DMEL derivations within this CSR -Linearised approach and Large assessment factor approach. Reasons for this were as follows:

If compared both approaches, the Large assessment factor approach resulted in less conservative estimates and Linearised approach represented more conservative approach (Restriction Report – Proposal for a Restriction, Annex XV, byFederal Institute for Occupational Safety and Health,,, 2010).

Worker population is relatively homogenous, if compared to general population, hence the less conservativeLarge assessment factor approach was used for DMEL derivation for workers.

Population of humans exposed via the environment includes sensitive subpopulations, e.g. children, pregnant women and elder people, hence the more conservative Linearised approach was used at the risk level 10^-5.

The whole range of DMELs is presented instead of taking the most sensitive DMEL from a single study, for both, workers and humans exposed via the environment, for all relevant routes of exposure. This is in accordance withthe Restriction Report - Proposal for a Restriction, Annex XV, byFederal Institute for Occupational Safety and Health (,, 2010)– mainly due to relatively high uncertainties in DMEL derivations. The lower interval limits represent the results of the most and upper interval limits the results of the least sensitive studies.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.07 mg/m³

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

300

Modified dose descriptor starting point:

LOAEC

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.04 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

1 200

Modified dose descriptor starting point:

LOAEL

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

DNEL related information

Local effects

Long term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

General Population - Hazard via oral route

Systemic effects

Long term exposure

Hazard assessment conclusion:

DNEL (Derived No Effect Level)

Value:

0.08 mg/kg bw/day

Most sensitive endpoint:

repeated dose toxicity

DNEL related information

Overall assessment factor (AF):

600

Modified dose descriptor starting point:

LOAEL

Acute/short term exposure

Hazard assessment conclusion:

no-threshold effect and/or no dose-response information available

DNEL related information

Additional information - General Population

Exposure pattern	Route	Descriptors	DNEL/DMEL (appropriate unit)	Most sensitive endpoint	Justification
Acute - systemic effects	Dermal (mg/kg bw /day)
	Inhalation (mg/m^3)
	Oral (mg/kg bw /day)
Acute - local effects	Dermal (mg/cm^2)
	Inhalation (mg/m^3)
Long-term - systemic effects	dermal(mg/kg bw /day)	Corr LOAEL = 50 mg/kg bw/d       HT25 0.006 – 0.013 mg BaP/kg bw/d	DNEL = 0.04  mg/kg bw/day         DMEL 0.034 – 0.074 ng BaP/kg bw/d	Liver and kidney damage, haematological alteration   Skin carcinoma, other skin tumors
	Inhalation (mg/m^3)	Corr LOAEC: 21.7 mg/m^3 HT25 2.52 - 6.24 μg BaP/m^3	DNEL = 0.07 mg/ m^3   DMEL 0.1 – 0.25 ng BaP/ m^3	Liver and kidney damage, haematological alteration   Lung tumors
	oral(mg/kg bw /day)	Corr LOAEL = 50 mg/kg bw/d         HT25 0.038-0.694 mg BaP/kg bw/d	DNEL = 0.08  mg/kg bw/day           DMEL 0.217 – 3.97 ng BaP/kg bw/d	Liver and kidney damage, haematological alteration Lung tumors, liver tumors, forestomach and small intestine tumors
Long-term – local effects	Dermal (mg/cm^2)
	Inhalation (mg/m^3)

Risk assessment of Tar, brown-coal, low temp., was performed, with chronic toxicity and carcinogenicity being the major health effects considered. The main source of uncertainty in this risk assessment represents the lack of specific data for Tar, brown-coal, low temp.For the test substance, both, threshold and non-threshold modes of action were assumed. Subsequently, quantitative and semi-quantitative risk assessments were performed and both, Derived No-Effect Level (DNEL) and Derived Minimal Effect Levels (DMELs) were derived. 

Concerning Derived No-Effect Level (DNEL) determination for non-carcinogenic effects, LOAEL of 50mg/kg bw/dbased on a subchronic study in rat exposed by oral gavage (VUOS, 2011) was used. The main health effects observed were liver and kidney toxicity, including structural and functional damage of the mentioned organs. Furthermore, irreversible alterations of hematologic parameters and atrophy of the genital organs in both sexes of tested animals were found.

Regarding carcinogenicity, within this risk assessment of Tar, brown-coal, low temp., due to the complex character of the test substance and a limited database available,the presence of its main contaminants - Polycyclic Aromatic Hydrocarbons (PAHs) and specifically Benzo(a)pyrene (BaP), was considered as an indicator of exposure to the Tar, brown-coal, low temp., using the same approach as in the EU Risk Assessment Report for Coal-Tar Pitch, high temperature (2008). However, compared to the Coal-Tar Pitch, high temperature, Tar, brown-coal, low temp., contains much lower levels of PAHs and specifically BaP. This fact must be kept in mind, when considering uncertainties with respect to this CSR. On the other hand, Tar, brown-coal, low temp., is classified as the Carcinogen 1A, mainly due to the presence of PAHs, so the primary aim of the risk reduction measures must be to minimize potential contact with the substance as much as possible.

As the primary indicator of PAHs, BaP, one of the most toxic PAHs and known carcinogen and mutagen, was considered. Thus, DMELs within this CSR are derived from data on BaP.

Although there is a lack of knowledge on health effects of other chemical constituents of Tar, brown-coal, low temp., it is very likely thatthe limitation of the risks for cancer will automatically reduce the risk for any other possible health effects. 

For DMELs calculations, dose descriptors – T25 – used in this assessment were taken from theRestriction Report – Proposal for a Restriction, Annex XV, byFederal Institute for Occupational Safety and Health (,, 2010), focused on the restriction of selected PAHs in consumer products. Although besides T25, BMD10 and BMDL10 were calculated in the mentioned report, T25 were chosen, because these dose descriptors could be derived directly from the studies without necessity of route-to-route extrapolation. For BMD10 and BMDL10, route-to-route extrapolation would be needed (no adequate inhalation studies) and consequently, uncertainty in this risk assessment would further increase.

Two different approaches were used for DMEL derivations within this CSR -Linearised approach and Large assessment factor approach. Reasons for this were as follows:

If compared both approaches, the Large assessment factor approach resulted in less conservative estimates and Linearised approach represented more conservative approach (Restriction Report – Proposal for a Restriction, Annex XV, byFederal Institute for Occupational Safety and Health,,, 2010).

Worker population is relatively homogenous, if compared to general population, hence the less conservativeLarge assessment factor approach was used for DMEL derivation for workers.

Population of humans exposed via the environment includes sensitive subpopulations, e.g. children, pregnant women and elder people, hence the more conservative Linearised approach was used at the risk level 10^-5.

The whole range of DMELs is presented instead of taking the most sensitive DMEL from a single study, for both, workers and humans exposed via the environment, for all relevant routes of exposure. This is in accordance withthe Restriction Report - Proposal for a Restriction, Annex XV, byFederal Institute for Occupational Safety and Health (,, 2010)– mainly due to relatively high uncertainties in DMEL derivations. The lower interval limits represent the results of the most and upper interval limits the results of the least sensitive studies.