Phenol, mono- + distyrenated (MSP+DSP)

Endpoint summary

Description of key information

In an acute oral toxicity study under GLP conditions according to OECD TG 423 applying phenol, styrenated as test substance at one concentration (limit test), the discriminating dose was determined to be 2000 mg/kg bw (discriminating dose = 2000 mg/kg).

In an acute inhalation toxicity study under GLP conditions according to OECD TG 403 applying the supporting substance phenol, methylstyrenated at one concentration (limit test), the LC50 was determined to be > 5 mg/L (LC0 = 5 mg/L).

In an acute dermal toxicity study under GLP conditions according to OECD TG 402 applying the supporting substance phenol, methylstyrenated at one concentration (limit test), the LD50 was determined to be > 2000 mg/kg bw (LD0 = 2000 mg/kg).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Novares LS 500; phenol, styrenated
- Source and lot/batch No.of test material: RÜTGERS Novares GmbH, batch No. 28324
- Composition of the test substance is specified in IUCLID Sect. 13 - Assessment reports under Certificate of Analysis_Novares LS 500_phenol, styrenated
- Substance type: organic
- Purity test date: 30.11.2012
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Tierzucht Schönwalde GmbH/Germany
- Age at study initiation: young adult
- Weight at study initiation: 140 - 182 g
- Fasting period before study: approx. 18 h
- Housing: polycarbonate cages
- Diet: ad libitum, except 3 - 4 h after treatment
- Water: ad libitum
- Acclimation period: 6 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +-3
- Humidity (%): 55 +-15
- Air changes (per hr): 10x
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 2 g/10 mL
- Amount of vehicle (if gavage): ~8 mL/kg bw
- Justification for choice of vehicle: miscible with the TS

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: 0, 7, and 14 d
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

not applicable

Key result

Sex:

male/female

Dose descriptor:

discriminating dose

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Sex:

male/female

Dose descriptor:

LD0

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Mortality:

none

Clinical signs:

other: piloerection, pinched abdomen, in isolated cases diarrhoea. No anomalities from day 4 post-application.

Gross pathology:

no particular findings

Other findings:

none

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

no classification required

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

In the study using phenol, mono- & distyrenated (LS 500), no mortality was observed. In this study as well as in the studies with the supporting substance phenol, methylstyrenated, the LD50 determined was always > 2000 mg/kg bw. Studies were conducted under GLP conditions. Reliability of the studies is 1.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Novares LA 300
- Source and lot/batch No. of test material: RÜTGERS Novares GmbH, batch No. 28166
- Composition of test material: composition is specified in IUCLID Sect. 13 - Assessment reports under Certificate of Analysis_Novares LA 300_phenol, methylstyrenated
- Substance type: organic
- Physical state: liquid
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable
- Storage condition of test material: room temperature, exclusion of light

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories Ltd, Oxon, UK.
- Age at study initiation: 8 - 12 wks
- Weight at study initiation: 270 - 284 g (m); 199 - 220 (f) [see Appendix 6]
- Fasting period before study: no
- Housing: solid-floor polypropylene cages, groups of 5 by sex
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: >= 5 d


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25
- Humidity (%): 30 - 70
- Air changes (per hr): >= 15x/h
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

other: diethyl ether

Mass median aerodynamic diameter (MMAD):

2.22 µm

Geometric standard deviation (GSD):

2.83

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Cylindrical exposure chamber
- Exposure chamber volume: approx. 30 litres (dimensions: 28 cm diameter x 50 cm high)
- Method of holding animals in test chamber: individually held in a tapered, polycarbonate restraining tube

- Method of conditioning air: Compressed air supplied by means of an oil free compressor and passed
through a water trap and respiratory quality filters before it was introduced to the nebuliser.
- Air flow through chamber: 60 L/min

- System of generating particulates/aerosols: Glass concentric jet nebuliser located at the top of the exposure chamber /
Nebuliser connected to a glass syringe attached to an infusion pump
providing the material formulation

- Method of particle size determination: 3x during the exposure, using a Marple Personal Cascade Impactor
with six impactor stages (9.0, 6.3, 4.0, 1.7, 0.81 and 0.30 µm cut points).
The collection substrates and backup filter were weighed before and after sampling
and the weight of test material, collected at each stage, calculated by difference
(Results in Report Fig. 3 and 4).

- Method of particle collection: by weighed glass fibre filter placed in a filter holder and temporarily sealed
in a vacant port of the exposure chamber in the animals’ breathing zone.

- Volatile / non-volatile fraction: The mean non-volatile component of the batch used during the study was found to be 98.6 % (n=10).

Procedure: Prior to the start of the study, the non-volatile component of the test material was determined
by adding a small, known amount of test material to glass fibre filters and recording their weights.
The filters were then kept in a desiccator between 19 and 20°C for approx. 24 h and then weighed again.
The difference in the two weights was taken as the volatile content of the test material and the non-volatile component
was calculated as a percentage.

- Treatment of exhaust air: bottom outlet through a "scrubber" trap, connected with a high efficiency filter to a metered exhaust system
- Temperature, humidity, pressure in air chamber: 19 - 20 °C, 39 - 47% (rel.hum.), slight low-pressure [Report, Appendix 9]


TEST ATMOSPHERE
- Brief description of analytical method used: particle/aerosol gravimetric determination
- Samples taken from breathing zone: yes


VEHICLE
- Composition of vehicle (if applicable): diethyl ether
- Concentration of test material in vehicle (if applicable): 50 % (w/w)
- Justification of choice of vehicle: high viscosity of the TS, to improve aerolisation of the TS


TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: ca. 72% (w/w) with aerodynamic diameter < 4 µm
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 2.22 / 2.83 µm

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetrically (aerosol)

Duration of exposure:

4 h

Concentrations:

Mean: 4.92 +-0.46 mg/L (n = 17) / nominal: 50.3 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: day 0, 7, 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:

Statistics:

For particle size: arithmetic mean + standard deviation / MMAD derived from probits of stage amounts plotted against Log10 cut-point size + geometric standard deviation / LD50: not relevant

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4.92 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Standard deviation of analytical determination: 0.46 mg/L

Sex:

male/female

Dose descriptor:

LC0

Effect level:

4.92 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Standard deviation of analytical determination: 0.46 mg/L

Mortality:

none

Clinical signs:

other: Hunched posture, pilo-erection, and increased respiratory rate commonly seen for short periods following 4h inhalation; isolated instance of lethargy / All female animals exhibited staining of the head and one also showed noisy respiration. 4 - 6 d after

Body weight:

One male with bw transiently reduced during week 1.
Normal bodyweight development was noted for all other animals during the course of the study.
[see Report Appendix 6]

Gross pathology:

No macroscopic abnormalities

The particle size analysis of the atmosphere drawn from the animals’ breathing zone, was as follows

[see Report Appendices 1 and 2]:

Mean Achieved Atmosphere Concentration +-SD [mg/L] (n = 17)	Mass Median Aerodynamic Diameter [µm] (n = 3)	Respirable Fraction [wt% <4 µm]	Geometric Standard Deviation [µm]
4.92 +-0.46	2.22	71.5	2.83

Conclusions:

No classification required

Reference 2

Endpoint:

acute 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:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The source substance LA 300 (Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol, previous name phenol, methylstyrenated) is produced by the same process as LS 500 (phenol, mono- & distyrenated, target substance). In both cases, one reactant is phenol. The second reactant is different being 2-phenylpropene and just styrene for LA 300 and LS 500 respectively.
During the manufacturing process (acid catalysed alkylation reaction), the starting monomeric reactants form di- or higher substituted/condensed products. Reaction products are on the one hand the alkylation products mono- and di-substituted phenol (LS 500 1-phenylethyl and LA 300 1-methyl-1-phenylethyl substituents, respectively). On the other hand, manufacture of LA 300 results, in addition to the 1-methyl-1-phenylethyl substituted phenols, also in di-/oligomerisation reaction products of the olefinic reaction component. Substituted phenol components of LA 300 and LS 500 differ only in one methyl group that in case of LA 300 is additionally attached to the bridging carbon atom, the substituents being 1-methyl-1-phenylethyl- (LA 300) and 1-phenylethyl- (LS 500), respectively.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Main difference between LA 300 and LS 500 is, that the production of LA 300 results in dimers and oligomers of 2-phenylpropene (olefinic reaction component) in addition to substituted phenols. These di/oligomers are purely alkylaromatic substances with no phenol moiety present. They are composed of an alkyl chain (C5 or longer) that carries two or more phenyl-rings (benzene moieties). Ratio of non-phenolic to phenolic substances in LA 300 is > 0.5.
Considering the method of aerosol generation (nebulisation of a test material dissolution in diethyl ether), behaviour of both substances as airborne fractions will be similar.

3. ANALOGUE APPROACH JUSTIFICATION
Use of LA 300 as supporting substance for LS 500 is justified because both substances contain very similar components (substituted phenols), which differ only in one methyl substituent at the bridging carbon chain. In addition, components with the same degree of condensation (equal number of aromatic rings) (either alkylated or di-/oligomerised products) are quite similar in size and have similar spatial arrangements of structural elements. Structural elements are basically the same for both substances, as components are comprised of aromatic rings (benzene and phenol or purely benzene) and of a smaller aliphatic chain, to which the aromatic moieties are attached. Due to the similarity of the structural elements, metabolism and biotransformation will proceed in a similar way. There will be attack at the aliphatic chain resulting in hydroxylated products that subsequently are transformed to aldehydes and carboxylic acids. Metabolism of the aromatic rings will also result in hydroxylated products. Thus, similar metabolites are formed for LA 300 and LS 500. Based on these grounds, it is justified to adopt results of toxicity tests obtained with the source substance LA 300 (phenol, methylstyrenated) for the target substance LS 500 (phenol, mono- & distyrenated).

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

Read-across to the preceding entry:
Source substance: Phenol, methylstyrenated - LA 300 (Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol)
Reference: Griffiths DR 2010

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4.92 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Standard deviation of analytical determination: 0.46 mg/L

Remarks:

effect level relates to the source substance; toxicity of the target substance is assumed to be similar to the source substance

Sex:

male/female

Dose descriptor:

LC0

Effect level:

4.92 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Standard deviation of analytical determination: 0.46 mg/L

Remarks:

effect level relates to the source substance; toxicity of the target substance is assumed to be similar to the source substance

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

4 920 mg/m³ air

Quality of whole database:

The study was conducted under GLP conditions according to OECD TG 403 using the supporting substance phenol, methylstyrenated. At the dose applied (limit test, 4920 mg/m³), no mortality was observed. But there were some clinical signs of toxicity related to CNS depression and irritation of the respiratory tract. Reliability of the study is 1.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19. 10. – 05. 11. 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Novares LA 300
- Source and lot/batch No. of test material: RÜTGERS Novares GmbH, batch No. 28166
- Composition of test material: composition is specified in IUCLID Sect. 13 - Assessment reports under Certificate of Analysis_Novares LA 300_phenol, methylstyrenated
- Substance type: organic
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable
- Storage condition of test material: room temperature, exclusion of light

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Breeding farm VELAZ s.r.o., Koleč u Kladna, Czech Republic
- Age at study initiation: no data, adult
- Weight at study initiation: 278 - 317 g (m); 203 - 223 g (f);
- Fasting period before study: no
- Housing: 1 animal/plastic cage
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +-3
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 / 12

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: about 6 x 6 cm
- % coverage: aprox. 10% of the body surface
- Type of wrap if used: mull and plaster (strapping)


REMOVAL OF TEST SUBSTANCE
- Washing (if done): water
- Time after start of exposure: 24 h

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Body weight: before application, 8th and 15th day of study
Mortality: daily
Clinical signs: daily
Pathological examination: 15th day of study

- Necropsy of survivors performed: yes

Statistics:

not applicable

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Sex:

male/female

Dose descriptor:

LD0

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Mortality:

none

Clinical signs:

other: after 3 h: piloerection in 9/10 animals, single cases with red secretion around eyes and decreased response to stimuli; after 2 d: no particular findings, but 1 female with skin irritation which healed by day 11.

Gross pathology:

no particular findings, but 1 female with discoloration of the liver (light colour)

Table No. 1: Individual body weight of animals – 2000 mg/kg – males

Animal No.	Before application	8th day	15th day	Body weight gain (g)
				day 0-8 p.a.	day 8-15 p.a.
1 (pre-test)	298.75	317.19	340.74	18.44	23.55
2	278.31	298.94	313.65	20.63	14.71
3	304.74	317.66	345.98	12.92	28.32
4	316.89	332.24	354.09	15.35	21.85
5	303.66	311.04	330.31	7.38	19.27
Average	300.47	315.41	336.95	14.94	21.54

Table No. 2: Individual body weight of animals – 2000 mg/kg – females

Animal No.	Before application	8th day	15th day	Body weight gain (g)
				day 0-8 p.a.	day 8-15 p.a.
1 (pre-test)	223.08	219.18	231.28	-3.90	12.1
2	223.42	216.23	223.05	-7.19	6.82
3	217.08	226.69	232.16	9.61	5.47
4	203.13	200.73	214.09	-2.40	13.36
5	204.65	200.79	204.00	-3.86	3.21
Average	214.27	212.72	220.92	-1.55	8.19

The test substance applied on skin at a dose of 2000 mg/kg of animal weight did not cause death of animals.    

Clinical signs of intoxication (piloerection, decreased response to stimuli, red secretion around eyes) were observed in all males and four females. Irritation on the skin was observed after application of the test substance in one female. Symptoms of irritation faded away on 12^thday after application of the test substance. Decreased body weight in females was recorded in period day 0-8 of the study. Macroscopic changes were diagnosed during pathological examination in one female (liver – light colour).

Reference 2

Endpoint:

acute toxicity: dermal

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The source substance LA 300 (Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol, previous name phenol, methylstyrenated) is produced by the same process as LS 500 (phenol, mono- & distyrenated, target substance). In both cases, one reactant is phenol. The second reactant is different being 2-phenylpropene and just styrene for LA 300 and LS 500 respectively.
During the manufacturing process (acid catalysed alkylation reaction), the starting monomeric reactants form di- or higher substituted/condensed products. Reaction products are on the one hand the alkylation products mono- and di-substituted phenol (LS 500 1-phenylethyl and LA 300 1-methyl-1-phenylethyl substituents, respectively). On the other hand, manufacture of LA 300 results, in addition to the 1-methyl-1-phenylethyl substituted phenols, also in di-/oligomerisation reaction products of the olefinic reaction component. Substituted phenol components of LA 300 and LS 500 differ only in one methyl group that in case of LA 300 is additionally attached to the bridging carbon atom, the substituents being 1-methyl-1-phenylethyl- (LA 300) and 1-phenylethyl- (LS 500), respectively.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Main difference between LA 300 and LS 500 is, that the production of LA 300 results in dimers and oligomers of 2-phenylpropene (olefinic reaction component) in addition to substituted phenols. These di/oligomers are purely alkylaromatic substances with no phenol moiety present. They are composed of an alkyl chain (C5 or longer) that carries two or more phenyl-rings (benzene moieties). Ratio of non-phenolic to phenolic substances in LA 300 is > 0.5.

3. ANALOGUE APPROACH JUSTIFICATION
Use of LA 300 as supporting substance for LS 500 is justified because both substances contain very similar components (substituted phenols), which differ only in one methyl substituent at the bridging carbon chain. In addition, components with the same degree of condensation (equal number of aromatic rings) (either alkylated or di-/oligomerised products) are quite similar in size and have similar spatial arrangements of structural elements. Structural elements are basically the same for both substances, as components are comprised of aromatic rings (benzene and phenol or purely benzene) and of a smaller aliphatic chain, to which the aromatic moieties are attached. Due to the similarity of the structural elements, metabolism and biotransformation will proceed in a similar way. There will be attack at the aliphatic chain resulting in hydroxylated products that subsequently are transformed to aldehydes and carboxylic acids. Metabolism of the aromatic rings will also result in hydroxylated products. Thus, similar metabolites are formed for LA 300 and LS 500. Based on these grounds, it is justified to adopt results of toxicity tests obtained with the source substance LA 300 (phenol, methylstyrenated) for the target substance LS 500 (phenol, mono- & distyrenated).

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

Read-across to the preceding entry:
Source substance: Phenol, methylstyrenated - LA 300 (Oligomerisation and alkylation reaction products of 2-phenylpropene and phenol)
Reference: Rösslerová Z, Mejstrik V 2009

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: effect level relates to the source substance; toxicity of the target substance is assumed to be similar to the source substance

Sex:

male/female

Dose descriptor:

LD0

Effect level:

2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: effect level relates to the source substance; toxicity of the target substance is assumed to be similar to the source substance

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Both studies were conducted as a limit test under GLP conditions according to OECD TG 402. No mortality was observed in both tests. Reliability of the studies is 1.

Additional information

In assessing the acute toxicity of phenol, mono- & distyrenated (Novares LS 500), the material phenol, methylstyrenated (LA 300, LA 700, and Necires EPX-L) is used as supporting substance. For endpoints not covered by data for phenol, mono- & distyrenated, studies with phenol, methylstyrenated are used as key studies. With respect to molecular weight, molecular structure, and lipophilicity, the substances are in a range that gastrointestinal absorption, distribution, and metabolism in mammals can be expected. Justification for read-across from phenol, methylstyrenated to phenol, mno- & distyrenated is presented in the corresponding endpoint study records.

 

Acute toxicity: oral

For assessment of the acute oral toxicity of phenol, mono- & distyrenated (Novares LS 500), one valid study is available (Schreiter/FREY-TOX 1999). This study is selected as key study. To confirm the result of this study, acute toxicity data of three studies using phenol, methylstyrenated (LA 300, LA 700, and Necires EPX-L) are employed as supporting evidence (LA 300, Albrecht/BSL 2007; LA 700, Albrecht/BSL 2007; Nev EPX, Daamen/NOTOX 1994). Tests were performed under GLP conditions, and reliability for all studies is 1. The reported discriminating dose/LD50 values are quite similar and demonstrate a low acute oral toxicity of the test substances. The similarity of results for both substances authenticates the use of phenol, methylstyrenated as supporting substance.

Phenol styrenated (LS 500): acute toxicity - oral

Schreiter/FREY-TOX 1999

In this valid acute oral toxicity study according to OECD TG 423 using five male and five female rats applying the test substance by gavage, a discriminating dose of 2000 mg/kg bw was determined for male and female rats. No mortality was observed in the study.

Phenol methylstyrenated (LA 300, LA 700, Necires EPX-L)

In an Acute Toxic Class Method test according to OECD TG 423, applying the test substance LA 300 by gavage at an initial dose of 2000 mg/kg bw, no mortality was observed, characterising the test substance as acute toxic Category V according to OECD GHS (no classification required) (Albrecht/BSL 2007).

Conducting the same test with LA 700, two animal died at the initial dose of 2000 mg/kg bw (1 out of 3 animal in each of the two starting groups) (Albrecht/BSL 2007).

In a study according to OECD TG 401, the LD50 of NECIRES EPX-L was determined to be > 2000 mg/kg bw (Daamen/NOTOX 1994).

In all tests presented above, it was demonstrated that the discriminating dose/LD50 was equal or higher than 2000 mg/kg bw.

Combined evidence of the data indicate, that phenol, mono- & distyrenated is of low acute oral toxicity.

 

Acute toxicity: inhalation

For assessment of the acute inhalation toxicity of phenol, mono- & distyrenated (LS 500), no data could be identified. Data for phenol, methylstyrenated (LA 300) as supporting substance will be used instead. Justification for read across is given in the corresponding endpoint study records. This study is used as key study.

Source substance phenol, methylstyrenated (LA 300)

LA 300 was tested in a valid acute inhalation toxicity study under GLP conditions according to OECD TG 403 (reliability 1) with rats as test species using a single test substance concentration of 4.92 mg/L (limit test). Test substance was applied as aerosol with a mean mass median aerodynamic diameter of 2.22 µm (n = 3) for four hours. The inhalable fraction was 71.5 % (aerodynamic diameter < 4 µm) of the total aerosol concentration. No mortality was observed during the 14 day observation period (0/10 animals died).

Thus the LC50 was determined to be > 4.92 mg/L (measured value) and the LC0 was 4.92 mg/L (Griffiths/Harlan 2010).

Target substance phenol, mono- & distyrenated (LS 500): acute toxicity - inhalation

It is justified to adopt the LC50 value of phenol, methylstyrenated for phenol, mono-& distyrenated as no mortality was observed for phenol, methylstyrenated at the limit concentration and both substances will act in a similar way in biological organisms as illustrated above. Due to the result (no mortality observed), there is a safety margin associated with the adoption of the LC50 value.

LC50 (aerosol) of phenol, mono- & distyrenated (LS 500) >= 4.92 mg/L (corresponding to a nominal value of 5 mg/L).

 

Acute toxicity: dermal

For assessment of the acute dermal toxicity of phenol, mono- & distyrenated (LS 500), no data could be identified. Data for phenol, methylstyrenated (LA 300, Necires EPX-L) as supporting substance will be used instead. Justification for read across is given in the corresponding endpoint study records. As the study with LA 300 (Rösslerova/VUOS 2009) uses semi-occlusive coverage of the exposed skin area as specified in current test guidelines contrary to the occlusive wrapping of the study with Necires EPX-L (Daamen/NOTOX 1994), the study of Rösslerova/VUOS 2009 is selected as key study.

Source substance phenol, methylstyrenated (LA 300, Necires EPX-L)

Both tests were performed under GLP conditions as limit tests according to OECD TG 402 (reliability 1). Five rats/sex were exposed to 2000 mg/kg bw of neat test substance under semi-occlusive (LA 300) or occlusive (Necires EPX-L) coverage for 24 hours. No mortality was observed during the 14 day observation period. A few animals showed signs of irritation at the site of application between day 5 and 15, being more pronounced for Necires EPX-L as for LA 300.

LD50 for both tests was > 2000 mg/kg bw. LD0 was 2000 mg/kg bw (Rösslerova/VUOS 2009; Daamen/NOTOX 1994).

Target substance phenol, mono-& distyrenated (LS 500): acute toxicity - dermal

It is justified to adopt the LD50 value of phenol, methylstyrenated for phenol, mono- & distyrenated (LD50 >= 2000 mg/kg bw), as no mortality was observed for phenol, methylstyrenated at the limit concentration and both substances will act in a similar way in biological organisms as illustrated above. Due to the test result (no mortality observed), there is a safety margin associated with the adoption of the LD50 value.

LD50 (dermal) for phenol, mono- & distyrenated (LS 500) >= 2000 mg/kg bw.

 

In key studies for acute toxicity of all three application routes, conducted as limit tests, no mortality was observed. LD/C50 values exceed the respective limit concentrations (2000 mg/kg bw and 5 mg/L respectively), the LD/C0 is equal to the limits. These data demonstrate the low acute toxicity of phenol, mono- & distyrenated.

Justification for classification or non-classification

For all three application routes, data from limit tests with concentrations set to the upper limit for classification are available. Mortality in all test was absent or low and distinct LD(C) 50 values could not be determined (LD(C)50 > limit concentration). Data demonstrate that criteria for classification of phenol, styrenated as acutely toxic are not met.