Anthracene oil

Endpoint summary

Description of key information

Oral route:

The repeated dose oral toxicity of anthracene oil (BaP < 50 ppm, AOL) is assessed using an oral TDI value (tolerable daily intake) of 0.04 mg/kg bw/day derived for phenanthrene by Baars et al./RIVM 2001, The Netherlands (see study record/reference 1). This evaluation is based on data for the aromatic >EC9-EC16 fraction. RfD/TDI values were derived for several constituents of the fraction from animal experimental data and a value best characterising the fraction (0.04 mg/kg bw/d) was estimated based on expert judgement. This value is considered to be a conservative estimate for individual components of the mixture with missing toxicity data.

Inhalation route:

Evaluation of the repeated dose inhalation toxicity of anthracene oil is based on information available from a sub-chronic study with the closely structure-related tar oil creosote. Exposure of rats to creosote aerosols for 90 days resulted in systemic and local toxic effects with a NOAEC of 5.4 and 22 mg/m³ (analytical and nominal concentration, respectively).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

repeated dose toxicity: oral, other

Remarks:

subchronic and chronic

Type of information:

experimental study

Remarks:

Review and evaluation of experimental data

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Peer-reviewed data, evaluation of current databases for deriving permissible exposure levels

Qualifier:

no guideline required

Principles of method if other than guideline:

RIVM project 711701 "Risk in relation to Soil Quality", RIVM Bilthoven/NL; the project has the aim to derive Maximum Permissible Risk levels (MPR) for the oral route and in isolated cases for inhalation based on available data. The evaluation comprises besides others chemical classes PAH including phenanthrene. The MPR(human) is defined as the amount of a substance (usually a chemical substance) that any human individual can be exposed to daily during lifetime without significant health risk..... For genotoxic carcinogens the MPR has been defined as the excess lifetime cancer risk of 1 in 10000 (1:10E4) (RIVM 2001 (Ref. 1), Chap. 2, p. 9). For substances causing threshold effects, MPRs are expressed as Tolerable Daily Intake (TDI) or Tolerable Concentration in Air (TCA) [see Results]. For background information on MPR see Janssen and Speijers 1997 (Ref. 2).

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): phenanthrene; generic substance as evaluated in the report Ref. 1.

Species:

other: mouse and rat

Strain:

other: various

Sex:

male/female

Details on test animals or test system and environmental conditions:

no data

Route of administration:

other: oral and inhalation

Vehicle:

not specified

Details on oral exposure:

not specified

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

not applicable

Frequency of treatment:

not applicable

No. of animals per sex per dose:

not applicable

Details on study design:

not applicable

Positive control:

not applicable

Observations and examinations performed and frequency:

not applicable

Sacrifice and pathology:

not applicable

Other examinations:

Evaluation of databases (see "Any other information..")

Details on results:

not applicable

Key result

Dose descriptor:

other: TDI (Tolerable Daily Intake)

Effect level:

0.04 other: mg/kg bw/day (lifelong for any human)

Based on:

other: evaluation of toxicity database of petroleum products

Sex:

male/female

Basis for effect level:

other: non-neoplastic effects, derived as mean/representative for the aromatic >EC9 to EC 21 fraction of TPH (total petroleum hydrocarbons)

Remarks on result:

other: amount of a substance that any human individual can be exposed to daily during lifetime without significant health risk

Key result

Dose descriptor:

other: TCA (Tolerable Concentration in Air)

Effect level:

0.14 other: mg/m³ (lifelong for any human)

Based on:

other: evaluation of toxicity database of petroleum products

Sex:

male/female

Basis for effect level:

other: non-neoplastic effects; value is derived from the oral TDI above, assuming an absorption rate of 100 % in either case: TCA = (TDI x 70 kg/bw) / (20 m³/d)

Remarks on result:

other: concentration of a substance in air that any human individual can be exposed to daily during lifetime without significant health risk

Key result

Dose descriptor:

NOAEL

Remarks:

for aromatic >EC9 to EC 21 fraction from TPH

Effect level:

120 other: mg/kg bw/day, mean for the TPH fraction

Based on:

other: evaluation of toxicity database of petroleum products

Sex:

male/female

Basis for effect level:

other: non-neoplastic effects, derived from TDI value by application of the correction factor (3000) used for RfD derivation (mean/representative for the aromatic >EC9 to EC 21 fraction of TPH)

Key result

Critical effects observed:

not specified

For methodology see above under ‘Any other information on materials and methods incl. tables’.

In the aromatic >EC9 to EC16 fraction, relevant for phenanthrene, 77 compounds have been identified: RfDs have been developed for 8 of these (all with ECs > 9), ranging from 0.03 to 0.3 mg/kg bw/day. There are also data available on a mixture within this range: naphthalene/methylnaphthalenes: for this mixture, a RfD of 0.03 mg/kg bw/day was developed. After reviewing the information, a fraction-specific RfD of 0.04 mg/kg bw/day was considered to be appropriate (based on the 8 individual RfDs, 4 of which were 0.04 mg/kg bw/day and considering the range of the remaining RfDs). The constituent pyrene is characteristic for the >EC16 to EC21 fraction. For this substance, a RfD of 0.03 mg/kg bw/day is available. As the RfD values are very similar, the fractions considered can be combined to an >EC9 to EC21 fraction. Taking into account the combined evidence, a fraction specific RfD of 0.04 mg/kg bw/day can be adopted for the combined fraction. This fraction specific RfD value is adopted for phenanthrene as constituent contained in this fraction.

For the RfD estimation of substances present in the fraction, uncertainty factors of 3000 have be used reflecting 10 each for intra- and interspecies variability, 10 for the use of sub-chronic studies for chronic RfD derivation, and an additional 3 for quality rating of the database. Thus, the RfD estimates can be considered to be quite conservative. RfDs and the experimental database for different PAH can be extracted from the US EPA IRIS data system (URL: https://cfpub.epa.gov/ncea/iris/search/index.cfm).

The fraction-specific RfD developed using the TPHCWG approach has been uses by RIVM as Maximum Permissible Risk (MPR) level. For threshold effects, the MPR is expressed as Tolerable Daily Intake (TDI, oral route).

Reliable RfCs for inhalation have not been identified. Therefore, oral TDI values are converted to tolerable concentrations in air (TCD values) covering inhalation exposure. TCA values can be derived from TDI values taking into account the body weight, the daily respiratory volume, and different absorption rates for oral and inhalation exposure using the following equation: TCF = (TDI x 70 kg x 100) / (20 m³ x 75). But assuming equal absorption rates for either route (more conservative approach), the equation reduces to TCA = TDI x 70 kg / 20 m³.

Conclusions:

For phenanthrene a TDI value of 40 µg/kg bw/day was established by evaluation of the oral repeated dose toxicity of an aromatic fraction of Total Petroleum Hydrocarbons (TPH). This fraction (ES>9 to 21) includes PAH from naphthalene to pyrene. A group TDI considered valid for PAH components in this mixture was developed by comparison of individual components of the mixture and selecting a most appropriate value for the total mixture.
The value derived is adopted for phenanthrene.

Reference 2

Endpoint:

repeated dose toxicity: oral, other

Remarks:

subchronic and chronic

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The source test substance is phenanthrene as constituent of the aromatic Total Petroleum Hydrocarbon (TPA) fraction ES>9 to 21. This fraction contains other polycyclic aromatic hydrocarbons in addition to phenanthrene (naphthalene to pyrene). Repeated dose toxicity data are evaluated taking into account other PAH besides phenanthrene.
The target substance anthracene oil (anthracene oil with < 50 ppm benzo[a]pyrene (BaP), AOL) is composed of a broad range of PAH but predominantly consisting of two to four aromatic rings. This range of PAH is very similar to the range of TPH-PAH evaluated for repeated dose toxicity of phenanthrene and the ES>9 to 21 TPA fraction.
The nature of both substances including constituents is considered to be sufficiently similar that systemic toxic effects after repeated oral application will also be similar. Therefore, the source substance (mixture) is suited as supporting substance with regard to repeated dose oral toxicity and data resulting from the source substance/mixture can be used for characterising the toxicological properties of the target substance anthracene oil.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Repeated dose toxicity data are evaluated in the source study with regard to several PAH constituents of the ES>9 to 21 TPH-fraction. Constituents range from naphthalene to pyrene. The goal of the study is to evaluate/develop toxic threshold levels for individual PAH and for the fraction as such taking into account the toxicity of individual components of the mixture (compound specific RfD values) and to draw conclusions for the fraction as a whole (fraction specific RfD/TDI).
The target material anthracene oil (< 50 ppm BaP, AOL) is a UVCB substance produced by the distillation of coal tars extracting the approximate distillation range from ca. 300 °C to 400 °C. 10 % to 95 % of the total product distil over between ca. 300 °C and 375 °C. The substance is a brown pasty or liquid material consisting of a complex and within limits variable combination of polycyclic aromatic hydrocarbons. The distillation range excludes mostly low molecular aromatic hydrocarbons (especially one-ring and to a lower extent two-ring aromatics) as well as polycyclic aromatic hydrocarbons composed of more than four to five rings depending on the respective boiling points of the individual aromatic substances. PAH identified in anthracene oil rang from naphthalene to pyrene with very low amounts of benzofluorenes included. This range of PAH is similar to the PAH in the TPH-ES>9 to ES21 fraction. Major constituent of anthracene oil is phenanthrene being present in concentrations from approx. 25 to 31 % (typical concentration). Due to its abundance in anthracene oil, it is selected as marker substance for toxic effects caused by anthracene oil.

3. ANALOGUE APPROACH JUSTIFICATION
Repeated dose toxicity by oral application depends on the uptake characteristics of a substance and on its toxicokinetic and toxicological properties. Systemic toxic effects will be caused after resorption from the gastrointestinal tract, metabolic activation and distribution within the body. In the case of complex substances/mixtures like UVCBs/TPH fractions, the overall toxicity will result from the effects caused by the individual components of the substance. If substances are similar, the systemic oral toxicity will be comparable.
The general composition of the source and target substance is similar. Relevant constituents are two-ring up to four-ring PAH. Marker substance for anthracene oil is phenanthrene. This substance is assessed to represent the systemic repeated dose toxicity of anthracene oil.
In the RIVM study (source study), a RfD for phenanthrene was derived based on the toxic properties of the ES>9 to ES21 TPH fraction. This fraction contains approximately the same PAH as anthracene oil. A RfD was developed that was considered to represent the total fraction and to be sufficiently conservative that it can be attributed to individual components of unknown toxicity within the fraction. Thus the resulting RfD specifies the toxicity of individual components as well as the mixture as a whole. This situation regarding the THP fraction is like the situation for anthracene oil and phenanthrene as constituent.
Taking this information into account, it is considered justified to use toxicity data of phenanthrene or the TPH ES>9 to ES 21 fraction in order to characterise toxic effects of anthracene oil.

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

Read-across to preceding entry:
Source test material: phenanthrene (generic, commercial product);
Reference: Baars et al. 2001

Key result

Dose descriptor:

other: TDI (Tolerable Daily Intake)

Effect level:

0.04 other: mg/kg bw/day (lifelong for any human)

Based on:

other: evaluation of toxicity database of petroleum products

Sex:

male/female

Basis for effect level:

other: non-neoplastic effects (see above)

Remarks on result:

other: the result of the source substance is adopted for the target substance anthracene oil

Key result

Dose descriptor:

NOAEL

Effect level:

120 other: mg/kg bw /day, mean for TPH fraction

Based on:

other: evaluation of toxicity database of petroleum products

Sex:

male/female

Basis for effect level:

other: non-neoplastic effects (see above)

Remarks on result:

other: the result of the source substance is adopted for the target substance anthracene oil

Key result

Critical effects observed:

not specified

Conclusions:

For phenanthrene, a TDI value of 40 µg/kg bw/day was established by evaluation of the oral repeated dose toxicity data (RfD values) of an aromatic fraction of Total Petroleum Hydrocarbons (TPH). This fraction (ES>9 to ES 21) includes PAH from naphthalene to pyrene. A group TDI considered valid for PAH components in this mixture was developed by comparison of individual components of the mixture and selecting a most appropriate value for the total mixture. The value derived this way was adopted for phenanthrene. A NOAEL of 120 mg/kg bw/day for phenanthrene was obtained by applying the same correction factor (3000) on the TDI value that was used for the derivation of the RfD values evaluated.
The derivation of the TDI value for phenanthrene is based on data for a TPH fraction that contains the same PAH as the target substance anthracene oil. Therefore, the TDI value as well as the NOAEL value established for phenanthrene are also valid for and can be applied to anthracene oil.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

0.04 mg/kg bw/day

Study duration:

chronic

Species:

other: related to humans

Quality of whole database:

Peer-reviewed derivation of a TDI value based on a comprehensive evaluation of available experimental data (rodent, subchronic)

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 82-4 (90-Day Inhalation Toxicity)

Qualifier:

according to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

detailed examination for clinical signs of toxicity was performed weekly instead of daily

Qualifier:

according to guideline

Guideline:

EU Method B.29 (Sub-Chronic Inhalation Toxicity:90-Day Study)

Deviations:

yes

Remarks:

detailed examination for clinical signs of toxicity was performed weekly instead of daily

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Creosote; North American P1/P13 Creosote; North American Creosote Composite Test Material P1/P13
- Composition of test material, percentage of components: see under Test material information

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Crl:CD® BR VAF/PLUS®

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Portage, Michigan, USA
- Age at study initiation: Approx. 6 weeks
- Weight at study initiation: Males: 181 - 211 g; females: 130 - 149 g

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

>= 2.2 - <= 3 µm

Geometric standard deviation (GSD):

1.99

Remarks on MMAD:

MMAD / GSD: MMAD [µm] (± GSD [µm])
Low dose: 3.0 (1.92)
Mid dose: 2.2 (1.99)
High dose: 2.4 (1.91)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Nominal concentration: Calculated from the amount of test compound used during the exposure period (by weighing the reservoir before and after the exposure period) and dividing the total creosote consumed by the total air volume passed through the chamber.
Analytical aerosol concentration: Determined by gravimetric determination of the oil amount adsorbed onto a 25-mm glass-fibre filter pad, divided by the sample volume. Volatile components of creosote will very likely be missed by this analytical method.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

6 h/d, 5 days per week

Dose / conc.:

22 mg/m³ air (nominal)

Remarks:

low dose - mean nominal concentration (total test material consumed)

Dose / conc.:

5.4 mg/m³ air (analytical)

Remarks:

low dose - mean measured aerosol concentration (gravimetric determination)

Dose / conc.:

128 mg/m³ air (nominal)

Remarks:

medium dose - mean nominal concentration (total test material consumed)

Dose / conc.:

49 mg/m³ air (analytical)

Remarks:

medium dose - mean measured aerosol concentration (gravimetric determination)

Dose / conc.:

221 mg/m³ air (nominal)

Remarks:

high dose - mean nominal concentration (total test material consumed)

Dose / conc.:

106 mg/m³ air (analytical)

Remarks:

high dose - mean measured aerosol concentration (gravimetric determination)

No. of animals per sex per dose:

20/sex/group; 10 of 20 animals/sex/dose were used for recovery examination (6 weeks recovery period subsequent to exposure period).
An additional group (5/sex) was sacrificed pre-test to define a baseline for clinical chemistry and haematological values.

Control animals:

yes, sham-exposed

Positive control:

none

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: weekly (including mortality)

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: pre-test and weekly

FOOD CONSUMPTION: Yes
- Time schedule: weekly

FOOD EFFICIENCY: No data

WATER CONSUMPTION: No

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to terminal necropsy and prior to recovery necropsy
- Dose groups that were examined: no data

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at termination of study or at the end of the recovery period on surviving animals
- Anaesthetic used for blood collection: no data
- Animals fasted: no data
- How many animals: pre-test: 5/sex; main study: 10/sex/group
- Parameters examined: haematocrit, haemoglobin, erythrocyte count, total and differential leukocyte count, platelet count, reticulocytes, MCV, MCH, MCHC

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at termination of study or at the end of the recovery period on surviving animals
- Animals fasted: no data
- How many animals: pre-test: 5/sex; main study: 10/sex/group
- Parameters examined: no data

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

ORGAN WEIGHT:
- Time schedule for examinations: at termination of the study or at the end of the recovery period
- How many animals: 10/group
- Dose groups that were examined: all dose groups
- Organs: adrenal, brain, ovary, testis with epididymis, heart, kidney, liver, lung, mammary gland, thymus, thyroid/parathyroid, trachea

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
All animals: external examination; contents of abdominal, thoracic and cranial cavities were examined both in situ and after removal and dissection.

HISTOPATHOLOGY: Yes
All animals: heart, thyroid, nasal tissues, trachea, and lung
Control and high dose group as well as animals that died on study: adrenal, aorta, auditory sebaceous gland, bone with bone marrow (femur), bone marrow smear, brain (fore, mid and hind), eye including optic nerve and contiguous Harderian gland, gastrointestinal tract, gonads, heart, kidney, larynx, lachrymal gland, liver, lung, lymph nodes, mammary gland (females only), nasal tissues, pancreas, pituitary, prostate and seminal vesicle, salivary gland, sciatic nerve, skeletal muscle (thigh), skin, spinal cord, spleen, thymus, thyroid/parathyroid, trachea, tracheal bifurcation, urinary bladder, vagina, uterus and cervix

Other examinations:

Ten animals per dose group and sex were subject to a six-week post-exposure period, after which they were sacrificed and examined macroscopically for reversibility of eventual effects.

Statistics:

Analysis of body weights, food consumption, clinical pathology laboratory tests and organ weights were performed as follows: Generally, when the number of animals in any one group was ≤ 10, non-parametric analysis was conducted using the KRUSKAL-WALLIS one-way analysis of variance, followed by the MANN-WHITNEY U test, where appropriate. In those cases where the number of animals in all groups was greater than ten and the measurements were on at least an interval scale (continuous data), parametric analysis was conducted utilizing BARTLETT’s chi-square test for homogeneity of variance, followed by an analysis of variance and then, where appropriate, by DUNNETT’s t-test.

Clinical signs:

no effects observed

Mortality:

mortality observed, non-treatment-related

Description (incidence):

1 dead animal (mid-dose group during week 4 of exposure)

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

week 1 all groups and week 3 high-dose males

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Histopathological findings: neoplastic:

not specified

Details on results:

CLINICAL SIGNS AND MORTALITY:
One male in the mid-dose group died during the exposure phase (week 4) of this study.

BODY WEIGHT AND WEIGHT GAIN
Body weight decreases were observed in the two highest exposure groups. They were significant in both sexes of the high-dose group and in mid-dose females during exposure week 6. Mean weights for the low-level group were similar to the control group.

FOOD CONSUMPTION:
With the exception of week 1 (all groups significantly less than controls) and week 3 (males in the high-dose group significantly less than controls), food consumption during the 13-week exposures and the six-week post-exposure recovery period was comparable to that of controls.

HAEMATOLOGY:
Several haematological parameters showed significant changes in the two highest exposure levels at the terminal sacrifice including: decreased erythrocytes, haemoglobin, and haematocrit; increased numbers of reticulocytes. These changes were not detectable at the end of the recovery period.

CLINICAL CHEMISTRY:
Serum cholesterol was significantly increased in males of the mid-dose group and in females of the two highest exposure groups. This change was not evident at the end of the recovery period (see table below).

ORGAN WEIGHTS:
Terminal sacrifice: There was a test-article-related and statistically significant increase in the lung/trachea/body weight ratio in males and females of the high-dose group when compared to the respective control values. These increases correlated with the macroscopic observation of grey discolouration of the lungs, and the microscopic observation of pigmented macrophages within the lungs of the animals in the affected groups. In mid- and high-dose males, the adrenal/body weight ratio was increased. No macroscopic or microscopic changes were associated with these changes.
In males, increases in liver weight (mid-dose group) and liver/body weight ratio (mid- and high-dose group) were noted. Relative liver weights were significantly increased at the mid and high dose (about +20 and +25 %, respectively).
In females, there were increases in liver weight (high-dose group), liver/body weight ratio (mid- and high-dose group) and liver/brain weight ratio (mid- and high-dose group) when compared to controls. No macroscopic or microscopic changes were associated with these changes, thus, their toxicological significance is uncertain.

Recovery sacrifice: There were no test-article-related changes in organ weight or weight ratios for males in any dose group. In mid-dose females, the mean adrenal weight was significantly decreased compared to controls. No macroscopic or microscopic observations were associated with that finding. Thus, it was deemed not test article related.

GROSS PATHOLOGY:
At the terminal sacrifice, a deposition of the test article consisting of a grey discolouration of the lung was seen at the two highest exposure levels. The discolouration persisted through the recovery period. The control and low-dose group

HISTOPATHOLOGY: NON-NEOPLASTIC:
Microscopic changes were observed in the hearts, lungs, nasal tissues, and thyroid glands of male and female rats at the time of terminal sacrifice.
Heart lesions were found in one male of the mid-dose group that died on the study, and in one male and one female of the high-dose group (diffuse myocardial degeneration affecting mainly the right side of the heart). Associated to this change was diffuse arterial medial hypertrophy of small arterioles in the lung, brown pigment within the epithelial cells of the convoluted tubules of the kidney, and in the animal that died on study, alveolar macrophages containing brown pigment consistent with haemosiderin (“heart failure cells”) within the lung and diffuse centrilobular fibrosis within the liver. No heart lesions were found in any dose group at the end of the recovery period.
Note: Cardiac pathology (ie: hemorrhage, lymphocytic infiltration and cardiomyopathy) was noted in all animals of all groups (including controls).

Test-article-related changes in the lung were seen in all animals of the exposed groups (small black pigment granules within alveolar macrophages). Alveolar macrophages containing pigment granules could be detected in all lobes of the lungs indicating a uniform dispersion of the test article throughout the alveolar spaces of the lungs. There were no other changes within the lungs, which could be associated with the presence of the granules, such as inflammation, increased number of pulmonary macrophages and/or Type-II pneumocyte hyperplasia. These findings were also seen at recovery sacrifice.

Nasal cavity: Small cystic spaces, containing basophilic mucoid material, within the olfactory epithelium at all levels of the nasal tissues examined and in both sexes, and were considered test article related. Mucoid cysts were seen in mid- and high-dose males, and in low-, mid-, and high-dose females. Similar findings were made at recovery sacrifice.
Other histological changes within the nasal tissues: Squamous metaplasia of respiratory and/or olfactory epithelium and naso­lachrymal duct epithelium, inflammatory cell infiltrates, and glandular dilation within the lamina propria/submucosa of the nasal cavity. These additional changes showed no definitive test article relationship.

Hypertrophy of thyroid follicular cells, which resulted in a reduction in the amount of colloid present within the thyroid follicles, was seen in both male and female rats of all exposure groups. This anomaly was considered test-article related. No test-article-related effects on the thyroid glands were detected at recovery sacrifice. There was no measurable effect on the mass of the thyroid gland (no changes in absolute and relative weights).

Key result

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on the death of one male, decreases in body-weight gain (> 10 %) as well as on the increase in liver weight (≥ 20 %), and on the increase in hypertrophy of follicular cells of the thyroid gland

Key result

Dose descriptor:

NOAEC

Remarks:

local, nasal

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: local chronic inflammation reactions in the nasal cavity in both sexes

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Dose descriptor:

NOAEC

Remarks:

local, nasal

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Dose descriptor:

LOAEC

Remarks:

systemic

Effect level:

128 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on the death of one male, decreases in body-weight gain (> 10 %) as well as on the increase in liver weight (≥ 20 %), and on the increase in hypertrophy of follicular cells of the thyroid gland

Dose descriptor:

LOAEC

Remarks:

local, nasal

Effect level:

128 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: local chronic inflammation reactions in the nasal cavity in both sexes

Dose descriptor:

LOAEC

Remarks:

systemic

Effect level:

49 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under nominal effect levels

Remarks on result:

other: volatile constituents may not or only partly be recorded by the analytical method

Dose descriptor:

LOAEC

Remarks:

local, nasal

Effect level:

49 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may not or only partly be recorded by the analytical method

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: hepatobiliary and endocrine system (systemic effects)

Organ:

liver

thyroid gland

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: respiratory system: upper respiratory tract (local effects)

Organ:

nasal cavity

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Results of clinical chemistry and haematology

Parameter changed	Unit	Controls 0 mg/m³		Low dose (nominal) 22 mg/m³		Medium dose (nominal) 128 mg/m³		High dose (nominal) 221 mg/m³
Time point		Terminal	Recovery	Terminal	Recovery	Terminal	Recovery	Terminal	Recovery
Males
Haemoglobin	g/dl	15.5	15.2	15.4	15.3	14.3**	15.0	14.6	15.1
Haematocrit	%	44.7	40.0	43.5	40.1	39.7*	39.7	40.3	39.8
Reticulocytes	/ 100 RBC	2.8	2.1	2.8	1.8	4.0	1.6	5.2	1.6
Phosphorus	mg/dl	7.6	7.0	8.9	6.9	8.3	6.7	8.5**	6.8
ALT	U/L	34	33	28	35	28	37	25*	31
Cholesterol	mg/dl	52	70	52	72	74*	69	70	78
Females
Haemoglobin	g/dl	15.4	15.0	15.3	15.5	14.6	15.5	13.5**	15.5
Haematocrit	%	41.4	38.8	40.9	39.6	37.8	39.6	35.0**	39.7
Reticulocytes	/ 100 RBC	2.9	2.3	3.0	2.2	3.4	2.0	7.8*	1.5
g-GT	U/L	1	3	1	1	3*	1	4*	2
Cholesterol	mg/dl	77	94	76	103	109**	99	116**	77

*  p≤ 0.05;              **p≤ 0.01

The effects observed showed reversibility during the recovery period.

Conclusions:

In a sub-chronic, 90 day, repeated dose, inhalation toxicity study with the test substance creosote, US-Type P1/P13, systemic and local adverse effects were observed that were test substance related. Systemic effects included mortality, changes in body and liver weight, and effects on the thyroid gland. Local effects appeared as chronic inflammation reaction in the nasal cavity in both sexes.
Doses were reported as nominal (total consumption of test substance) and analytical (gravimetric determination of the aerosol concentration) values (22, 128, and 221 mg/m³ and 5.4, 49, and 106 mg/m³, respectively). As analytical method, collection of the aerosol on a glass fibre filter and determination of the weight increase of the filter was used. By this method, volatile components of creosote will very likely escape analysis, and airborne concentrations measured will be to low. Therefore, effect levels will be based on nominal concentrations.
Consequently, the NOAEC for systemic and for local effects of creosote in this study was determined to be 22 mg/m³.

Reference 2

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The source test material creosote (US type P1/P13) consists predominantly of polycyclic aromatic hydrocarbons (PAH) ranging in size from two up to five fused rings. The target substance anthracene oil (anthracene oil with < 50 ppm benzo[a]pyrene (BaP), AOL) is as well composed of a broad range of PAH but predominantly consisting of two to four aromatic rings.
The nature of both substances and their constituents are considered to be sufficiently similar that systemic toxic effects observed following repeated inhalation exposure to aerosols are equivalent. Therefore, the source substance is suited as supporting substance with regard to repeated dose inhalation toxicity and data resulting from the source substance can be used for characterising the repeated dose systemic toxicological properties of the target substance anthracene oil upon aerosolic inhalation exposure.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The source material creosote (US type P1/P13) is a condensation product in the distillation of coal tars that have been obtained in the high temperature carbonisation of bituminous coal. The material is a UVCB substance forming a dark brown oily liquid. It is only partly volatile and consists of a complex mixture of polycyclic aromatic hydrocarbons with no or only a minimal content of other components (phenols). Two- and three-ring aromatics amount to about 40 % (typical concentration) with two-ring aromatics forming the smaller fraction. PAH with four and more rings accumulate to about 14 %. Five-ring PAH are only present in low concentration (below 0.3 % for individual substances). The water solubility of creosote is relatively low. It is determined by the solubility properties of its constituents.
The target material anthracene oil (AOL) is a UVCB substance as well produced by the distillation of coal tars extracting the approximate distillation range from ca. 300 °C to 400 °C. 10 % to 95 % of the total product distil over between ca. 300 °C and 375 °C. The substance is a brown pasty or liquid material consisting of a complex and within limits variable combination of polycyclic aromatic hydrocarbons. The distillation range excludes mostly low molecular weight aromatic hydrocarbons (especially one-ring and to a lower extent two-ring aromatics) as well as polycyclic aromatic hydrocarbons composed of more than four to five rings depending on the respective boiling points of the individual aromatic substances. Two- and three-ring aromatics amount to about 50 % (typical concentration) with two-ring aromatics forming the smaller fraction. PAH with four and more rings accumulate to about 10 % with pyrene and benzofluorenes representing the highest molecular weight PAH found in AOL. The water solubility of AOL is low being limited by the solubility properties of its constituents.

3. ANALOGUE APPROACH JUSTIFICATION
Composition of both substances is somewhat different creosote having a broader spectrum of PAH with a higher concentration of two-ring and a smaller concentration of three-ring PAH compared to AOL. The amount of four-ring PAH is similar for both substances but creosote contains a broader range of five-ring PAH (low concentrations). Basically, the same PAH are present in both substances and their consistency is quite similar.
Upon aerolisation, components of both substances will be transferred into the respiratory air and are after inhalation available for uptake into and distribution within the body. Besides formation of aerosol droplets, constituents of both substances will vaporise. Smaller molecules tend to vaporise more easily and tend to remain distributed in air for a longer period of time compared to larger molecules. Thus, it can be assumed that the fraction of two-ring PAH is increased in aerosols (vapour phase) compared to the liquid state of the substances. Still, concentration of two-ring PAH will be higher in aerosols of creosote compared to AOL, while concentration of three-ring PAH will be lower.
Considering the repeated dose toxicity of two- and three-ring PAH, moderate differences in the concentration of constituents in the aerosols (vapour and droplets) of both substances are considered to be of minor importance to the overall toxic effects caused by the substances after inhalation. Toxicokinetic parameters are similar. All PAH have similar metabolic activation pathways and will result in similar final toxicants. Within a range, effects are considered to be comparable. Repeated dose toxic effects observed after inhalation exposure of creosote by aerosols are assumed to similarly develop from exposure to AOL. For these reasons, it is considered justified to use toxicity data of creosote in order to characterise toxic effects of anthracene oil.

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

Read-across to preceding entry:
Source test material: Creosote - US type P1/P13;
Reference: Hilaski 1995

Key result

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on the death of one male, decreases in body-weight gain (> 10 %) as well as on the increase in liver weight (≥ 20 %), and on the increase in hypertrophy of follicular cells of the thyroid gland

Remarks on result:

other: the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Key result

Dose descriptor:

NOAEC

Remarks:

local, nasal

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: local chronic inflammation reactions in the nasal cavity in both sexes

Remarks on result:

other: the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Remarks:

the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Dose descriptor:

NOAEC

Remarks:

local nasal

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Remarks:

the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: hepatobiliary and endocrine system (systemic effects)

Organ:

liver

thyroid gland

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: respiratory system: upper respiratory tract (local effects)

Organ:

nasal cavity

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Conclusions:

In a sub-chronic, 90 day, repeated dose, inhalation toxicity study with the test (source) substance creosote, US-Type P1/P13, systemic and local adverse effects were observed that were test substance related. Systemic effects included mortality, changes in body and liver weight, and effects on the thyroid gland. Local effects appeared as chronic inflammation reaction in the nasal cavity in both sexes.
Doses were reported as nominal (total consumption of test substance) and analytical (gravimetric determination of the aerosol concentration) values (22, 128, and 221 mg/m³ and 5.4, 49, and 106 mg/m³, respectively). As analytical method, collection of the aerosol on a glass fibre filter and determination of the weight increase of the filter was used. By this method, volatile components of creosote will very likely escape analysis, and airborne concentrations measured will be to low. Therefore, effect levels will be based on nominal concentrations.
Consequently, the NOAEC for systemic and for local effects of creosote was determined to be 22 mg/m³.
This value is adopted for the target substance anthracene oil.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

22 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

Results obtained from a structure-related tar oil. NOAEC is based on nominal value as the analytical method is not adequate and underestimates exposure.

System:

other: hepatobiliary, endocrine system

Organ:

liver

thyroid gland

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Reference 1

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 82-4 (90-Day Inhalation Toxicity)

Qualifier:

according to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

detailed examination for clinical signs of toxicity was performed weekly instead of daily

Qualifier:

according to guideline

Guideline:

EU Method B.29 (Sub-Chronic Inhalation Toxicity:90-Day Study)

Deviations:

yes

Remarks:

detailed examination for clinical signs of toxicity was performed weekly instead of daily

GLP compliance:

yes

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Creosote; North American P1/P13 Creosote; North American Creosote Composite Test Material P1/P13
- Composition of test material, percentage of components: see under Test material information

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Crl:CD® BR VAF/PLUS®

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Portage, Michigan, USA
- Age at study initiation: Approx. 6 weeks
- Weight at study initiation: Males: 181 - 211 g; females: 130 - 149 g

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

>= 2.2 - <= 3 µm

Geometric standard deviation (GSD):

1.99

Remarks on MMAD:

MMAD / GSD: MMAD [µm] (± GSD [µm])
Low dose: 3.0 (1.92)
Mid dose: 2.2 (1.99)
High dose: 2.4 (1.91)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Nominal concentration: Calculated from the amount of test compound used during the exposure period (by weighing the reservoir before and after the exposure period) and dividing the total creosote consumed by the total air volume passed through the chamber.
Analytical aerosol concentration: Determined by gravimetric determination of the oil amount adsorbed onto a 25-mm glass-fibre filter pad, divided by the sample volume. Volatile components of creosote will very likely be missed by this analytical method.

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

6 h/d, 5 days per week

Dose / conc.:

22 mg/m³ air (nominal)

Remarks:

low dose - mean nominal concentration (total test material consumed)

Dose / conc.:

5.4 mg/m³ air (analytical)

Remarks:

low dose - mean measured aerosol concentration (gravimetric determination)

Dose / conc.:

128 mg/m³ air (nominal)

Remarks:

medium dose - mean nominal concentration (total test material consumed)

Dose / conc.:

49 mg/m³ air (analytical)

Remarks:

medium dose - mean measured aerosol concentration (gravimetric determination)

Dose / conc.:

221 mg/m³ air (nominal)

Remarks:

high dose - mean nominal concentration (total test material consumed)

Dose / conc.:

106 mg/m³ air (analytical)

Remarks:

high dose - mean measured aerosol concentration (gravimetric determination)

No. of animals per sex per dose:

20/sex/group; 10 of 20 animals/sex/dose were used for recovery examination (6 weeks recovery period subsequent to exposure period).
An additional group (5/sex) was sacrificed pre-test to define a baseline for clinical chemistry and haematological values.

Control animals:

yes, sham-exposed

Positive control:

none

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: weekly (including mortality)

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly

BODY WEIGHT: Yes
- Time schedule for examinations: pre-test and weekly

FOOD CONSUMPTION: Yes
- Time schedule: weekly

FOOD EFFICIENCY: No data

WATER CONSUMPTION: No

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to terminal necropsy and prior to recovery necropsy
- Dose groups that were examined: no data

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at termination of study or at the end of the recovery period on surviving animals
- Anaesthetic used for blood collection: no data
- Animals fasted: no data
- How many animals: pre-test: 5/sex; main study: 10/sex/group
- Parameters examined: haematocrit, haemoglobin, erythrocyte count, total and differential leukocyte count, platelet count, reticulocytes, MCV, MCH, MCHC

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at termination of study or at the end of the recovery period on surviving animals
- Animals fasted: no data
- How many animals: pre-test: 5/sex; main study: 10/sex/group
- Parameters examined: no data

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

ORGAN WEIGHT:
- Time schedule for examinations: at termination of the study or at the end of the recovery period
- How many animals: 10/group
- Dose groups that were examined: all dose groups
- Organs: adrenal, brain, ovary, testis with epididymis, heart, kidney, liver, lung, mammary gland, thymus, thyroid/parathyroid, trachea

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
All animals: external examination; contents of abdominal, thoracic and cranial cavities were examined both in situ and after removal and dissection.

HISTOPATHOLOGY: Yes
All animals: heart, thyroid, nasal tissues, trachea, and lung
Control and high dose group as well as animals that died on study: adrenal, aorta, auditory sebaceous gland, bone with bone marrow (femur), bone marrow smear, brain (fore, mid and hind), eye including optic nerve and contiguous Harderian gland, gastrointestinal tract, gonads, heart, kidney, larynx, lachrymal gland, liver, lung, lymph nodes, mammary gland (females only), nasal tissues, pancreas, pituitary, prostate and seminal vesicle, salivary gland, sciatic nerve, skeletal muscle (thigh), skin, spinal cord, spleen, thymus, thyroid/parathyroid, trachea, tracheal bifurcation, urinary bladder, vagina, uterus and cervix

Other examinations:

Ten animals per dose group and sex were subject to a six-week post-exposure period, after which they were sacrificed and examined macroscopically for reversibility of eventual effects.

Statistics:

Analysis of body weights, food consumption, clinical pathology laboratory tests and organ weights were performed as follows: Generally, when the number of animals in any one group was ≤ 10, non-parametric analysis was conducted using the KRUSKAL-WALLIS one-way analysis of variance, followed by the MANN-WHITNEY U test, where appropriate. In those cases where the number of animals in all groups was greater than ten and the measurements were on at least an interval scale (continuous data), parametric analysis was conducted utilizing BARTLETT’s chi-square test for homogeneity of variance, followed by an analysis of variance and then, where appropriate, by DUNNETT’s t-test.

Clinical signs:

no effects observed

Mortality:

mortality observed, non-treatment-related

Description (incidence):

1 dead animal (mid-dose group during week 4 of exposure)

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

week 1 all groups and week 3 high-dose males

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Neuropathological findings:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

see under Details on results

Histopathological findings: neoplastic:

not specified

Details on results:

CLINICAL SIGNS AND MORTALITY:
One male in the mid-dose group died during the exposure phase (week 4) of this study.

BODY WEIGHT AND WEIGHT GAIN
Body weight decreases were observed in the two highest exposure groups. They were significant in both sexes of the high-dose group and in mid-dose females during exposure week 6. Mean weights for the low-level group were similar to the control group.

FOOD CONSUMPTION:
With the exception of week 1 (all groups significantly less than controls) and week 3 (males in the high-dose group significantly less than controls), food consumption during the 13-week exposures and the six-week post-exposure recovery period was comparable to that of controls.

HAEMATOLOGY:
Several haematological parameters showed significant changes in the two highest exposure levels at the terminal sacrifice including: decreased erythrocytes, haemoglobin, and haematocrit; increased numbers of reticulocytes. These changes were not detectable at the end of the recovery period.

CLINICAL CHEMISTRY:
Serum cholesterol was significantly increased in males of the mid-dose group and in females of the two highest exposure groups. This change was not evident at the end of the recovery period (see table below).

ORGAN WEIGHTS:
Terminal sacrifice: There was a test-article-related and statistically significant increase in the lung/trachea/body weight ratio in males and females of the high-dose group when compared to the respective control values. These increases correlated with the macroscopic observation of grey discolouration of the lungs, and the microscopic observation of pigmented macrophages within the lungs of the animals in the affected groups. In mid- and high-dose males, the adrenal/body weight ratio was increased. No macroscopic or microscopic changes were associated with these changes.
In males, increases in liver weight (mid-dose group) and liver/body weight ratio (mid- and high-dose group) were noted. Relative liver weights were significantly increased at the mid and high dose (about +20 and +25 %, respectively).
In females, there were increases in liver weight (high-dose group), liver/body weight ratio (mid- and high-dose group) and liver/brain weight ratio (mid- and high-dose group) when compared to controls. No macroscopic or microscopic changes were associated with these changes, thus, their toxicological significance is uncertain.

Recovery sacrifice: There were no test-article-related changes in organ weight or weight ratios for males in any dose group. In mid-dose females, the mean adrenal weight was significantly decreased compared to controls. No macroscopic or microscopic observations were associated with that finding. Thus, it was deemed not test article related.

GROSS PATHOLOGY:
At the terminal sacrifice, a deposition of the test article consisting of a grey discolouration of the lung was seen at the two highest exposure levels. The discolouration persisted through the recovery period. The control and low-dose group

HISTOPATHOLOGY: NON-NEOPLASTIC:
Microscopic changes were observed in the hearts, lungs, nasal tissues, and thyroid glands of male and female rats at the time of terminal sacrifice.
Heart lesions were found in one male of the mid-dose group that died on the study, and in one male and one female of the high-dose group (diffuse myocardial degeneration affecting mainly the right side of the heart). Associated to this change was diffuse arterial medial hypertrophy of small arterioles in the lung, brown pigment within the epithelial cells of the convoluted tubules of the kidney, and in the animal that died on study, alveolar macrophages containing brown pigment consistent with haemosiderin (“heart failure cells”) within the lung and diffuse centrilobular fibrosis within the liver. No heart lesions were found in any dose group at the end of the recovery period.
Note: Cardiac pathology (ie: hemorrhage, lymphocytic infiltration and cardiomyopathy) was noted in all animals of all groups (including controls).

Test-article-related changes in the lung were seen in all animals of the exposed groups (small black pigment granules within alveolar macrophages). Alveolar macrophages containing pigment granules could be detected in all lobes of the lungs indicating a uniform dispersion of the test article throughout the alveolar spaces of the lungs. There were no other changes within the lungs, which could be associated with the presence of the granules, such as inflammation, increased number of pulmonary macrophages and/or Type-II pneumocyte hyperplasia. These findings were also seen at recovery sacrifice.

Nasal cavity: Small cystic spaces, containing basophilic mucoid material, within the olfactory epithelium at all levels of the nasal tissues examined and in both sexes, and were considered test article related. Mucoid cysts were seen in mid- and high-dose males, and in low-, mid-, and high-dose females. Similar findings were made at recovery sacrifice.
Other histological changes within the nasal tissues: Squamous metaplasia of respiratory and/or olfactory epithelium and naso­lachrymal duct epithelium, inflammatory cell infiltrates, and glandular dilation within the lamina propria/submucosa of the nasal cavity. These additional changes showed no definitive test article relationship.

Hypertrophy of thyroid follicular cells, which resulted in a reduction in the amount of colloid present within the thyroid follicles, was seen in both male and female rats of all exposure groups. This anomaly was considered test-article related. No test-article-related effects on the thyroid glands were detected at recovery sacrifice. There was no measurable effect on the mass of the thyroid gland (no changes in absolute and relative weights).

Key result

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on the death of one male, decreases in body-weight gain (> 10 %) as well as on the increase in liver weight (≥ 20 %), and on the increase in hypertrophy of follicular cells of the thyroid gland

Key result

Dose descriptor:

NOAEC

Remarks:

local, nasal

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: local chronic inflammation reactions in the nasal cavity in both sexes

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Dose descriptor:

NOAEC

Remarks:

local, nasal

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Dose descriptor:

LOAEC

Remarks:

systemic

Effect level:

128 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on the death of one male, decreases in body-weight gain (> 10 %) as well as on the increase in liver weight (≥ 20 %), and on the increase in hypertrophy of follicular cells of the thyroid gland

Dose descriptor:

LOAEC

Remarks:

local, nasal

Effect level:

128 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: local chronic inflammation reactions in the nasal cavity in both sexes

Dose descriptor:

LOAEC

Remarks:

systemic

Effect level:

49 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under nominal effect levels

Remarks on result:

other: volatile constituents may not or only partly be recorded by the analytical method

Dose descriptor:

LOAEC

Remarks:

local, nasal

Effect level:

49 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may not or only partly be recorded by the analytical method

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: hepatobiliary and endocrine system (systemic effects)

Organ:

liver

thyroid gland

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: respiratory system: upper respiratory tract (local effects)

Organ:

nasal cavity

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Results of clinical chemistry and haematology

Parameter changed	Unit	Controls 0 mg/m³		Low dose (nominal) 22 mg/m³		Medium dose (nominal) 128 mg/m³		High dose (nominal) 221 mg/m³
Time point		Terminal	Recovery	Terminal	Recovery	Terminal	Recovery	Terminal	Recovery
Males
Haemoglobin	g/dl	15.5	15.2	15.4	15.3	14.3**	15.0	14.6	15.1
Haematocrit	%	44.7	40.0	43.5	40.1	39.7*	39.7	40.3	39.8
Reticulocytes	/ 100 RBC	2.8	2.1	2.8	1.8	4.0	1.6	5.2	1.6
Phosphorus	mg/dl	7.6	7.0	8.9	6.9	8.3	6.7	8.5**	6.8
ALT	U/L	34	33	28	35	28	37	25*	31
Cholesterol	mg/dl	52	70	52	72	74*	69	70	78
Females
Haemoglobin	g/dl	15.4	15.0	15.3	15.5	14.6	15.5	13.5**	15.5
Haematocrit	%	41.4	38.8	40.9	39.6	37.8	39.6	35.0**	39.7
Reticulocytes	/ 100 RBC	2.9	2.3	3.0	2.2	3.4	2.0	7.8*	1.5
g-GT	U/L	1	3	1	1	3*	1	4*	2
Cholesterol	mg/dl	77	94	76	103	109**	99	116**	77

*  p≤ 0.05;              **p≤ 0.01

The effects observed showed reversibility during the recovery period.

Conclusions:

In a sub-chronic, 90 day, repeated dose, inhalation toxicity study with the test substance creosote, US-Type P1/P13, systemic and local adverse effects were observed that were test substance related. Systemic effects included mortality, changes in body and liver weight, and effects on the thyroid gland. Local effects appeared as chronic inflammation reaction in the nasal cavity in both sexes.
Doses were reported as nominal (total consumption of test substance) and analytical (gravimetric determination of the aerosol concentration) values (22, 128, and 221 mg/m³ and 5.4, 49, and 106 mg/m³, respectively). As analytical method, collection of the aerosol on a glass fibre filter and determination of the weight increase of the filter was used. By this method, volatile components of creosote will very likely escape analysis, and airborne concentrations measured will be to low. Therefore, effect levels will be based on nominal concentrations.
Consequently, the NOAEC for systemic and for local effects of creosote in this study was determined to be 22 mg/m³.

Reference 2

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The source test material creosote (US type P1/P13) consists predominantly of polycyclic aromatic hydrocarbons (PAH) ranging in size from two up to five fused rings. The target substance anthracene oil (anthracene oil with < 50 ppm benzo[a]pyrene (BaP), AOL) is as well composed of a broad range of PAH but predominantly consisting of two to four aromatic rings.
The nature of both substances and their constituents are considered to be sufficiently similar that systemic toxic effects observed following repeated inhalation exposure to aerosols are equivalent. Therefore, the source substance is suited as supporting substance with regard to repeated dose inhalation toxicity and data resulting from the source substance can be used for characterising the repeated dose systemic toxicological properties of the target substance anthracene oil upon aerosolic inhalation exposure.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The source material creosote (US type P1/P13) is a condensation product in the distillation of coal tars that have been obtained in the high temperature carbonisation of bituminous coal. The material is a UVCB substance forming a dark brown oily liquid. It is only partly volatile and consists of a complex mixture of polycyclic aromatic hydrocarbons with no or only a minimal content of other components (phenols). Two- and three-ring aromatics amount to about 40 % (typical concentration) with two-ring aromatics forming the smaller fraction. PAH with four and more rings accumulate to about 14 %. Five-ring PAH are only present in low concentration (below 0.3 % for individual substances). The water solubility of creosote is relatively low. It is determined by the solubility properties of its constituents.
The target material anthracene oil (AOL) is a UVCB substance as well produced by the distillation of coal tars extracting the approximate distillation range from ca. 300 °C to 400 °C. 10 % to 95 % of the total product distil over between ca. 300 °C and 375 °C. The substance is a brown pasty or liquid material consisting of a complex and within limits variable combination of polycyclic aromatic hydrocarbons. The distillation range excludes mostly low molecular weight aromatic hydrocarbons (especially one-ring and to a lower extent two-ring aromatics) as well as polycyclic aromatic hydrocarbons composed of more than four to five rings depending on the respective boiling points of the individual aromatic substances. Two- and three-ring aromatics amount to about 50 % (typical concentration) with two-ring aromatics forming the smaller fraction. PAH with four and more rings accumulate to about 10 % with pyrene and benzofluorenes representing the highest molecular weight PAH found in AOL. The water solubility of AOL is low being limited by the solubility properties of its constituents.

3. ANALOGUE APPROACH JUSTIFICATION
Composition of both substances is somewhat different creosote having a broader spectrum of PAH with a higher concentration of two-ring and a smaller concentration of three-ring PAH compared to AOL. The amount of four-ring PAH is similar for both substances but creosote contains a broader range of five-ring PAH (low concentrations). Basically, the same PAH are present in both substances and their consistency is quite similar.
Upon aerolisation, components of both substances will be transferred into the respiratory air and are after inhalation available for uptake into and distribution within the body. Besides formation of aerosol droplets, constituents of both substances will vaporise. Smaller molecules tend to vaporise more easily and tend to remain distributed in air for a longer period of time compared to larger molecules. Thus, it can be assumed that the fraction of two-ring PAH is increased in aerosols (vapour phase) compared to the liquid state of the substances. Still, concentration of two-ring PAH will be higher in aerosols of creosote compared to AOL, while concentration of three-ring PAH will be lower.
Considering the repeated dose toxicity of two- and three-ring PAH, moderate differences in the concentration of constituents in the aerosols (vapour and droplets) of both substances are considered to be of minor importance to the overall toxic effects caused by the substances after inhalation. Toxicokinetic parameters are similar. All PAH have similar metabolic activation pathways and will result in similar final toxicants. Within a range, effects are considered to be comparable. Repeated dose toxic effects observed after inhalation exposure of creosote by aerosols are assumed to similarly develop from exposure to AOL. For these reasons, it is considered justified to use toxicity data of creosote in order to characterise toxic effects of anthracene oil.

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

Read-across to preceding entry:
Source test material: Creosote - US type P1/P13;
Reference: Hilaski 1995

Key result

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on the death of one male, decreases in body-weight gain (> 10 %) as well as on the increase in liver weight (≥ 20 %), and on the increase in hypertrophy of follicular cells of the thyroid gland

Remarks on result:

other: the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Key result

Dose descriptor:

NOAEC

Remarks:

local, nasal

Effect level:

22 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: local chronic inflammation reactions in the nasal cavity in both sexes

Remarks on result:

other: the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Dose descriptor:

NOAEC

Remarks:

systemic

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Remarks:

the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Dose descriptor:

NOAEC

Remarks:

local nasal

Effect level:

5.4 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

aerosolic fraction

Sex:

male/female

Basis for effect level:

other: see effects above under effect level (nominal)

Remarks on result:

other: volatile constituents may have not or only partly been recorded by the analytical method

Remarks:

the test result of the source substance is adopted as weight of evidence for the target substance anthracene oil

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: hepatobiliary and endocrine system (systemic effects)

Organ:

liver

thyroid gland

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Key result

Critical effects observed:

yes

Lowest effective dose / conc.:

128 mg/m³ air (nominal)

System:

other: respiratory system: upper respiratory tract (local effects)

Organ:

nasal cavity

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Conclusions:

In a sub-chronic, 90 day, repeated dose, inhalation toxicity study with the test (source) substance creosote, US-Type P1/P13, systemic and local adverse effects were observed that were test substance related. Systemic effects included mortality, changes in body and liver weight, and effects on the thyroid gland. Local effects appeared as chronic inflammation reaction in the nasal cavity in both sexes.
Doses were reported as nominal (total consumption of test substance) and analytical (gravimetric determination of the aerosol concentration) values (22, 128, and 221 mg/m³ and 5.4, 49, and 106 mg/m³, respectively). As analytical method, collection of the aerosol on a glass fibre filter and determination of the weight increase of the filter was used. By this method, volatile components of creosote will very likely escape analysis, and airborne concentrations measured will be to low. Therefore, effect levels will be based on nominal concentrations.
Consequently, the NOAEC for systemic and for local effects of creosote was determined to be 22 mg/m³.
This value is adopted for the target substance anthracene oil.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

22 mg/m³

Study duration:

subchronic

Species:

rat

Quality of whole database:

Results obtained from a structure-related tar oil. NOAEC is based on nominal value as the analytical method is not adequate and underestimates exposure.

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No repeated dose toxicity data could be identified for anthracene oil (BaP < 50 ppm; AOL) [CAS no. 90640 -80 -5] itself. Thus, information from other substances is used as substitute. Repeated dose toxicity data is available for phenanthrene (oral route) and for the closely structure-related tar oil creosote (inhalation route). These substances will be used as supporting substances.

Anthracene oil is a UVCB substance and consists of a complex combination of polycyclic aromatic hydrocarbons. It comprises mainly two- and three-ring aromatic compounds (ca. 50 %, typical concentration) with two-ring aromatics forming the smaller fraction. PAHs with ≥ 4 rings are present to a lesser extent (< ca. 10 %, see Chapter 1.). In the EU, anthracene oil is not classified as carcinogenic based on its composition. Benzo[a]pyrene is present in concentrations below 50 ppm and other higher molecular weight PAH with clear experimental evidence for carcinogenicity are not present in AOL. Thus, repeated dose toxicity is assessed based on non-carcinogenic threshold effects.

Main component of AOL is phenanthrene. It is present in AOL in concentrations of 25 to 31 % (typical concentration, composite sample 7). Phenanthrene is considered to be among the PAH with the most pronounced effects resulting from non-carcinogenic repeated dose toxicity. Therefore, phenanthrene is used as supporting substance for repeated dose toxicity of AOL.

Creosote is produced in a similar process as anthracene oil (fractionated distillation of coal tar using overlapping conditions). Consequently, composition of both substances is quite similar. Major components are mid-range PAH (naphthalene to pyrene). Individual differences in distillation conditions and in starting material may cause gradual variations in qualitative and quantitative composition. Hence, the concentration of (carcinogenic) higher molecular weight PAH (e.g. benzo[a]pyrene) may be ≥ 50 ppm in contrast to AOL. But nevertheless, the basic nature of constituents and the individual components coincide, and the percentage of single substances is of the same magnitude. Toxicological effects regarding repeated dose toxicity for threshold effects of both substances will approximately be the same. Creosote can be used as supporting substance for the repeated dose toxicity of AOL.

Supporting substances phenanthrene and other PAH contained in AOL

Sub-chronic/chronic non-carcinogenic and carcinogenic effects of PAH including phenanthrene have been evaluated by RIVM (National Institute for Public Health and the Environment, Ministry of Health, Welfare and Sport, The Netherlands) in an extensive study (Baars AJ et al. 2001, RIVM Report 711701 025). The authors analysed the sub-chronic/chronic toxicity (non-carcinogenic and carcinogenic effects) of 17 PAH using a variety of sources (RIVM Report, Appendix 4. - Polycyclic aromatic hydrocarbons, pp. 143 ff.). In a first step, the PAH having a carcinogenic potential were identified. In a second step, maximum tolerable risk levels were developed (cancer risk values based on 1:10.000 excess lifetime cancer risk for oral exposure and TDI (tolerable daily intake) values - the estimated amount of a chemical that humans can ingest daily during their entire lifetime without resultant adverse health effects). In the deduction of cancer risk levels, relative carcinogenic potency factors were use (US EPA 1993 and Kalberlah et al. 1995) with the potency factor of benzo[a]pyrene defined as 1.

Non-carcinogenic toxicity was evaluated following the approach of the US Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) and the US Agency for Toxic Substances and Disease Registry (ATSDR) (RIVM report, Appendix 7.6. - Total Petroleum Hydrocarbons (TPH), p 280 ff.). In this approach, aromatic hydrocarbons containing fractions of Total Petroleum Hydrocarbons were examined regarding available repeated dose toxicity data. The selection of fractions was based on the equivalent carbon number index (EC). This index characterises hydrocarbons of the same size/number of carbon atoms as they would be eluted from a boiling point GC-column being normalised to n-alkanes. The fraction EC>9 to EC16 contains phenanthrene and other PAH relevant for anthracene oil. Toxicity data and related RfD/TDI values were identified for several constituents of the fraction. By analysing these data (mostly RfD values of US EPA originating from NOAELs, US EPA IRIS summaries), a value best characterising the fraction was estimated based on expert judgement (TDI = 0.04 mg/kg bw/day). This value can be used in order to specify the repeated dose toxicity of substances of unknown toxicity present in the fraction.

For phenanthrene, no definite repeated dose toxicity data have been located. Therefore, the value representative for the total fraction is adopted to specify the long-term repeated dose toxicity of phenanthrene (TDI: 0.04 mg/kg bw/day). This TDI value was derived from animal experimental data (90 d oral, repeated dose toxicity studies with mice) applying an uncertainty factor of 3000. Using this factor, a 'typical' subchronic, oral, repeated dose NOAEL for phenanthrene can be recalculated resulting in a value of 120 mg/kg bw/day.

In order to include PAH up to pyrene into the evaluation, the THP fraction has to be extended to EC21. Pyrene is the substance that characterises the repeated dose toxicity of this fraction. An RfD/TDI value of 0.03 mg/kg bw/day is reported (US EPA, IRIS summary). This value is close to the TDI for phenanthrene and the EC>9 to EC 16 fraction (0.04 mg/kg bw/day).

Combined risk estimation levels of the 17 PAH are reported in Tables 5 and 6 of the RIVM report (p 149 and 150). Four of these have been evaluated not to be carcinogenic (naphthalene, fluorene, anthracene, benzo[g,h,i]perylene). Other organisations may have identified another range of PAH as non-carcinogenic/carcinogenic (e.g. US EPA, IARC). For substances assessed in the RIVM report as having a low carcinogenic potency (low cancer risk levels), Tables 5 and 6 in combination show, that TDI estimates (individual TDI values based on TPH fraction) can be lower than the estimated cancer risk. This applies for example to acenaphthene and pyrene (cancer risk 0.5 mg/kg bw/day and TDI 0.04 or 0.03 mg/kg bw/day, respectively, see above).

Relevant constituents of anthracene oil are PAH ranging approx. from naphthalene to pyrene. Besides PAH assumed not to be carcinogenic, there are some PAH identified as having a low carcinogenic potential (low cancer risk values). The TDI values derived for these substances are lower than the cancer risk values estimated. Therefore, it is more appropriate to assess the repeated dose toxicity of these substances based on their repeated dose toxicity potential.

TDI values derived for constituents of anthracene oil fall into a narrow range (0.04 mg/kg bw/day for components of the EC>9 to EC16 fraction and 0.03 mg/kg bw/day for EC>16 to EC21 fraction or pyrene respectively). Taking into account this information as well as the quantitative composition of AOL, a TDI of 0.04 mg/kg bw/day can be adopted for anthracene oil as such. This value is assessed to characterise best the combined repeated dose toxicity of the UVCB substance anthracene oil.

Creosote

Creosote was used as test substance in a 90-day inhalation toxicity study according to US EPA TG OPP 82-4 and OECD TG 413 under GLP conditions. Rats were exposure to an aerosol (MMAD 2.2 to 3.0 m, potentially completely respirable) for 6 hours per day and five days per week. Low-grade toxicity was noted and the NOAEC(90 d) has been estimated to be 5.4 mg/m³ (analytical concentration, gravimetric determination) and 22 mg/m³ (nominal concentration, total consumption of test substance), respectively.

The analytical method consisted of the collection of the aerosol on a glass fibre filter and determination of the weight increase of the filter. By this method, volatile components of creosote will very likely escape analysis, and airborne concentrations measured will be too low. Therefore, effect levels will be based on nominal concentrations that include gas and particle phase.

Target organs were the nasal epithelium (irritation, inflammation), the lung (deposition of test material without significant histopathological changes), the liver (increase without histopathological changes), and thyroid gland (hypertrophy). All effects were reversible within a recovery period of six weeks.

References:

US EPA (1993) Provisional Guidance for Quantitative Risk Assessment of Polycyclic Aromatic Hydrocarbons. EPA/600/R-93/089, Environmental Criteria and Assessment Office, U.S. Environmental Protection Agency, Cincinnati, OH 45268 (URL: https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=49732

Kalberlah F, Frijus-Plessen N, Hassauer M (1995) Toxikologische Kriterien für die Gefährdungsabschätzung von polyzyklischen aromatischen Kohlenwasserstoffen (PAK) in Altlasten. Teil 1 -Verwendung von Äquivalenzfaktoren.Altlasten-Spektrum 5, 231-237

Justification for classification or non-classification

The low severity, the unspecific character as well as the reversibility of the findings do not justify the need for classification of anthracene oil for specific target toxicity.