Aromatic hydrocarbons, C10-13, reaction products with branched nonene, sulfonated, sodium salts

Endpoint summary

Description of key information

Sodium akylnaphthalene sulfonate (high and low nonone) is severely irritating to the skin, and causes irreversible eye damage.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 - 28 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000, including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Kisslegg, Germany
- Age at study initiation: at least 6 weeks old.
- Weight at study initiation: at least 1.0 kg.
- Housing: Animals were housed individually in cages with perforated floors.
- Diet: Free access to pelleted diet for rabbits (Global Diet 2030 from Harlan Teklad, Italy). Hay and wooden sticks were available during the study period.
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, approximately 15 room air changes/hour, and a 12-hour light/12-hour dark cycle.
Temporary deviations from the maximum level of daily mean relative humidity occurred. Laboratory historical data do not indicate an effect of the deviations.

IN-LIFE DATES: From: 14 - 28 May 2012

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

other: The test substance was moistened with 0.4 mL water

Controls:

other: Adjacent areas of the untreated skin of the animal served as control.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 grams

VEHICLE
The test substance was moistened with 0.4 mL water

Duration of treatment / exposure:

Single application.

Observation period:

14 days.

Number of animals:

1 male

Details on study design:

STUDY DESIGN
The study was performed in a stepwise manner and started with the treatment of one animal (sentinel) with a stepwise exposure regime. Based on the severity of the skin reactions, no further animals were exposed.

TEST SUBSTANCE PREPARATION
The powdery test substance was moistened with water (Elix, Millipore S.A.S., Molsheim, France), immediately before application, to ensure close contact with the animal's skin. No correction was made for purity of the test substance.

TEST SITE
This animal received 0.5 grams of the test substance moistened with 0.4 mL of the vehicle, to the intact, clipped skin of one flank using a Metalline patch1# of 2x3 cm. The patch was mounted on Micropore tape#, which was wrapped around the abdomen and secured with Coban elastic bandage#.
The dressing was removed 3 minutes after application. Since no signs of severe skin reactions (i.e. necrosis or corrosion) were observed and it was
considered that exposure could be continued humanely, two samples of 0.5 grams of the test substance moistened with 0.4 mL of the vehicle were then applied to separate skin-sites on the intact, clipped skin of the same animal, using an identical procedure and one sample per dressing. One of the dressings was removed after a 1-hour exposure. After similar considerations (i.e. no severe skin reactions, necrosis or corrosion), the other dressing was removed after a 4-hour exposure. After each removal of a dressing, the treated skin was cleaned of residual test substance using water.

REMOVAL OF TEST SUBSTANCE
After the application, the dressing was removed and the skin cleaned of residual test substance using tap water.

OBSERVATIONS (kort allemaal!)
- Mortality/Viability: Twice daily.
- Toxicity: At least once daily.
- Body Weight: Day of treatment (prior to application) and after the final observation.
- Necropsy:No necropsy was performed according to protocol.
- Irritation: The skin reactions of all visible treated sites were assessed immediately after removal of a dressing and approximately 1, 24, 48, 72 hours after the removal of the last dressing and test substance. For the duration of the skin reactions, further observations were made 7 and 14 (maximum) days after exposure. The irritation scores and a description of all other (local) effects were recorded. Adjacent areas of untreated skin of the animal serve as controls.

SCORING SYSTEM:
The irritation was assessed according to the numerical scoring system according to OECD 404.

Irritation parameter:

erythema score

Basis:

animal #1

Remarks:

(mean)

Time point:

24/48/72 h

Score:

3.7

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

edema score

Basis:

animal #1

Remarks:

(mean)

Time point:

24/48/72 h

Score:

4

Max. score:

4

Reversibility:

not reversible

Irritant / corrosive response data:

A 3-minute exposure resulted in well-defined erythema and slight oedema. The irritation had resolved within 72 hours following exposure.
A 1-hour exposure resulted in well-defined erythema and slight oedema. The irritation had resolved within 7 days following exposure.
A 4-hour exposure resulted in brown discolouration of the skin (a sign of superficial necrosis; due to which the maximum grade for erythema (grade 4) was assigned) at 48 and 72 hours and 7 days after exposure, severe oedema, reduced flexibility of the skin at 72 hours after exposure, fissuring of the skin at 7 days after exposure, and a bald skin with scaliness at 14 days after exposure.

There was no evidence of a corrosive effect on the skin.

Other effects:

Coloration/remnants: No staining of or remnants on the treated skin was observed.

Toxicity/mortality: No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

INDIVIDUAL SKIN IRRITATION SCORES

Animal 34#	3 minutes treatment site			1-hour treatment site			4-hours treatment site
Time after bandage removal	Erythema	Oedema	Comments	Erythema	Oedema	Comments	Erythema	Oedema	Comments
Immediately	2	2	-	2	2	-	2	3	-
1 hour	1	2	-	NS	NS	-	2	4	-
3 hours	NS	NS	-	1	2	-	NS	NS	-
4 hours	1	1	-	1	2	-	NS	NS	-
5 hours	1	1	-	NS	NS	-	NS	NS	-
24 hours	1	1	-	1	2	-	3	4	-
48 hours	0	1	-	1	2	-	4	4	k
72 hours	0	0	-	0	1	-	4	4	k, f
7 days	0	0	-	0	0	-	4	-	k, g
14 days	0	0	-	0	0	-	0	2	h, l

Comments:

NS. Not scored according to protocol.

-. No scoring possible due to fissuring of the skin and brown discolouration of the skin (sign of necrosis).

f. Reduced flexibility of the skin.

g. Fissuring of the skin.

h. Bald skin.

k. Brown discoloration, a sign of necrosis (superficial).

l. Scaliness.

MEAN VALUE IRRITATION SCORES AFTER 4 HOURS OF EXPOSURE

Animal #	Mean 24, 48 and 72 hrs
	Erythema	Oedema
34	3.7	4.0

# Animal specifications:
Animal no	Sex	Age at start	Body weights (grams)
		(weeks)	prior to application	at termination
34	♂	13-15	3419	3605

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Remarks:

Migrated information

Conclusions:

No evidence of full thickness destruction of the skin or scar tissue was observed during the observation period, indicating that no corrosion of the skin had occurred by dermal application of Sodium alkylnaphthalene sulfonate to the intact rabbit skin. The extreme response following a 4-hour exposure to Sodium alkylnaphthalene sulfonate in a single animal was irreversible within the 14-day observation period.

Executive summary:

Primary skin irritation/corrosion study with Sodium alkylnaphthalene sulfonate in the rabbit (semiocclusive application). The GLP compliant study was carried out according to OECD No.404 (2002); "Acute Toxicity - Skin irritation". One rabbit was exposed to three samples of 0.5 grams of Sodium alkylnaphthalene sulfonate applied to separate skin-sites on intact, clipped skin using a semi-occlusive dressing. The exposure periods were 3 minutes, 1 hour and 4 hours, respectively. Skin reactions were assessed at least once daily on Days 1-4 and 7 and 14 days after exposure. Based on the severity of the skin reactions, no further animals were exposed.

A 3-minute and 1-hour exposure resulted in well-defined erythema and slight oedema. The irritation had resolved within 72 hours or 7 days following exposure, respectively.

A 4-hour exposure resulted in brown discolouration of the skin (a sign of superficial necrosis; due to which the maximum grade for erythema (grade 4) was assigned) at 48 and 72 hours and 7 days after exposure, severe oedema, reduced flexibility of the skin at 72 hours after exposure, fissuring of the skin at 7 days after exposure, and a bald skin with scaliness at 14 days after exposure.

No evidence of full thickness destruction of the skin or scar tissue was observed during the observation period, indicating that no corrosion of the skin had occurred by dermal application of Sodium alkylnaphthalene sulfonate to the intact rabbit skin.

The extreme response following a 4-hour exposure to Sodium alkylnaphthalene sulfonate in a single animal was irreversible within the 14-day observation period.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 April - 15 May 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nohsan, Notification No 8147, April 2011, including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

- Source: Charles River France, L’Arbresle Cedex, France
- Age at study initiation: Animals used within the study were 12 - 13 weeks old.
- Weight at study initiation: Body weights were between 2577 - 3172 kg.
- Housing: Individually housed in cages with perforated floors.
- Diet: Free access to pelleted diet for rabbits (Global Diet 2030 Harlan Teklad, Italy). Hay and wooden sticks were available during the study period.
- Water: Free access to tap water.
- Acclimation period: At least 5 days

Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, approximately 15 room air changes/hour, and a 12-hour light/12-hour dark cycle. Any variations to these conditions were maintained in the raw data and had no effect on the outcome of the study.

IN-LIFE DATES: From: 02 April - 15 May 2014

Vehicle:

unchanged (no vehicle)

Controls:

other: One eye of each animal remained untreated and served as the reference control.

Amount / concentration applied:

TEST MATERIAL- Amount(s) applied (volume or weight with unit): 92.6 mg (range 92.4 – 92.9 mg)

Duration of treatment / exposure:

Single instillation on Day 1.

Observation period (in vivo):

The eyes of each animal were examined approximately 1, 24, 48 and 72 hours and 7, and 14 days after instillation of the test substance for one animal and 1, 24, 48 and 72 hours and 6, 7, 14 and 21 days after instillation for two animals.

Number of animals or in vitro replicates:

3 males

Details on study design:

PREEMPRIVE PAIN MANAGEMENT
Approximately one hour prior to instillation of the test substance, buprenorphine (Buprenodale®, Dechra Ltd., Stoke-on-Trent, United Kingdom) 0.01 mg/kg was administered by subcutaneous injection in order to provide a therapeutic level of systemic analgesia. Approximately five minutes prior to instillation of the test substance, two drops of the topical anesthetic lidocaïne eyedrops (AST Farma BV, Oudewater, The Netherlands) were applied to both eyes.

STUDY DESIGN
The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). The two other animals were treated in a similar manner three weeks later, after considering the degree of eye irritation observed in the first animal..

TREATMENT
Animals were treated by instillation of, on average, 92.6 mg (range 92.4 – 92.9 mg) of the test substance (a volume of approximately 0.1 mL), in the conjunctival sac of one of the eyes after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second to prevent loss of the test substance. The other eye remained untreated and served as the reference control. Immediately after the 24-hour observation, a solution of 2% fluorescein (Merck, Darmstadt, Germany) in water (adjusted to pH 7.0) was instilled into both eyes of each animal to quantitatively determine corneal epithelial damage. This procedure was repeated to assess recovery. Any bright green stained area, indicating epithelial damage, was estimated as a percentage of the total corneal area. Immediately after fluorescein examination on Day 2, in order to provide a continued level of systemic analgesia, buprenorphine 0.01 mg/kg and meloxicam (Metacam®, Boehringer Vetmed GmbH, Ingelheim/Rhein, Germany) 0.5 mg/kg were administered by subcutaneous injection.
Additional injections were supplied for all animals during the observation period to reduce pain and distress:
Time Description anaesthetic procedure
After 1 hr observation *1 sc 0.01 mg/kg buprenorphine
End of day *1 sc 0.01 mg/kg buprenorphine
After 24 hr obs end of the day *2 sc 0.03 mg/kg buprenorphine
After 48 hr observation *3 sc 0.01 mg/kg buprenorphine
After 48 hr observation *3 sc 0.5 mg/kg meloxicam

sc = subcutaneous injection.
*1 Due to score 3 for conjunctivae at 1-hr observation.
*2 Only for animal nos. 667 and 670.
*3 Due to score 3 for cornea and/or conjunctivae at 48 hr observation.

After the final observation, the animals were sacrificed by intra-venous injection of Euthasol® 20% (AST Farma BV, Oudewater, The Netherlands).

REMOVAL OF TEST SUBSTANCE
-Washing: No

OBSERVATIONS
- Mortality/Viability: Twice daily.
- Toxicity: At least once daily.
- Body Weight: Day of treatment (prior to instillation) and after the final observation.
- Necropsy: No necropsy was performed according to protocol.
- Irritation:The eyes of each animal were examined approximately 1, 24, 48 and 72 hours and 7, and 14 days after instillation of the test substance for one animal and 1, 24, 48 and 72 hours and 6, 7, 14 and 21 days after instillation for two animals. The irritation scores and a description of all other (local) effects were recorded.

SCORING SYSTEM:
The irritation was assessed according to the numerical scoring system according to OECD 405.

Irritation parameter:

cornea opacity score

Remarks:

(opacity)

Basis:

mean

Remarks:

(3 animals)

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: reversible in two animals, the third animal showed slightly dulling of the normal lustre of cornea

Irritation parameter:

iris score

Basis:

mean

Remarks:

(3 animals)

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Remarks:

(redness)

Basis:

mean

Remarks:

(3 animals)

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 21 Days

Remarks on result:

other: Reversible in two animals and the third animal showed slightly erythema

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

(3 animals)

Time point:

24/48/72 h

Score:

2.33

Max. score:

4

Reversibility:

fully reversible

Irritant / corrosive response data:

Irritation and Corrosion: Instillation of approximately 93 mg of Sodium akylnaphthalene sulfonate (low nonene) (a volume of approximately 0.1 mL) into one eye of each of three rabbits resulted in effects on the cornea, iris and conjunctivae. The corneal injury consisted of opacity and epithelial damage. As a result of the corneal injury, pannus (neovascularization of the cornea) was apparent in all animals at 6 and/or 7 days after instillation for two animals, or between 6 and 21 days after instillation for one animal. The corneal injury resolved within 14 days in two animals, but slight dulling of the normal luster remained present up to the end of the observation period (21 days) in the other animal. Iridial irritation was observed in all animals and resolved within 6 or 7 days. The irritation of the conjunctivae consisted of redness, chemosis and discharge and completely resolved within 14 days in two animals, but redness remained present up to the end of the observation period (21 days) in the other animal. Reduced elasticity of the yelids was noted for one anima (no. 670) on Days 6 and 7. Gray-white discolouration of the nictating membrane (a sign of necrosis) was noted for one animal (no. 670) from 24 hours following instillation onwards.

Other effects:

Colouration/Remnants: No staining of (peri) ocular tissues by the test substance was observed and no test substance remnants were seen.

Toxicity/Mortality: No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Interpretation of results:

Category I

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Sodium akylnaphthalene sulfonate (low nonene) showed irreversible effects in the eye of one of three rabbits tested, and should be GHS classified as having irreversible effects on the eyes (Category 1).

Executive summary:

Acute eye irritation/corrosion study with Sodium akylnaphthalene sulfonate (low nonene) in the rabbit. The study was carried out based on the guidelines described in OECD No.405 (2012) "Acute Eye Irritation / Corrosion".

 

Single samples of approximately 93 mg of Sodium akylnaphthalene sulfonate (low nonene) (a volume of approximately 0.1 mL) were instilled into one eye of each of three rabbits. Observations were made 1, 24, 48 and 72 hours and 7, and 14 days after instillation for one animal and 1, 24, 48 and 72 hours and 6, 7, 14 and 21 days after instillation for two animals.

Instillation of the test substance resulted in effects on the cornea, iris and conjunctivae.

The corneal injury consisted of opacity and epithelial damage. As a result of the corneal injury, pannus (neovascularization of the cornea) was apparent in all animals at 6 and/or 7 days after instillation for two animals, or between 6 and 21 days after instillation for one animal. The corneal injury resolved within 14 days in two animals, but slight dulling of the normal luster remained present up to the end of the observation period (21 days) in the other animal. Iridial irritation was observed in all animals and resolved within 6 or 7 days. The irritation of the conjunctivae consisted of redness, chemosis and discharge and completely resolved within 14 days in two animals, but redness remained present up to the end of the observation period (21 days) in the other animal. Reduced elasticity of the eyelids was noted for one anima (no. 670) on Days 6 and 7. Gray-white discolouration of the nictating membrane (a sign of necrosis) was noted for one animal (no. 670) from 24 hours following instillation onwards.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion:

Available historical results from in vivo skin irritation/corrosion studies involve a preparation of Sodium akylnaphthalene sulfonate (low nonene) which includes about 35% LAS which is a severe skin irritant (Kuhn, 1995). Other available data is not sufficient for classification for skin as they involve 24 hrs exposure, or only a 50% solution tested (Wallace, 1975).

 

In vitro skin irritation test (OECD 439, EPISKIN) with Sodium akylnaphthalene sulfonate (low nonene) resulted to a tissue viability of 34% compared to control following 15 minutes treatment. As this was below 50% it is considered to be irritating to skin.

 

Also a solution of 50% Sodium akylnaphthalene sulfonate (high nonene) was tested in an in vitros kin irritation test (OECD 439, EPISKIN). This resulted to a tissue viability of 105% after 15 minutes treatment, and was therefore considered to be non-irritant. In order to confirm the suggested non-irritating properties of Sodium akylnaphthalene sulfonatein vivo, a primary skin irritation/corrosion study was conducted with Sodium alkylnaphthalene sulfonate (high nonene) in the rabbit (semiocclusive application) according to OECD 404. One rabbit was exposed to three samples of 0.5 grams of Sodium alkylnaphthalene sulfonate applied to separate skin-sites on intact, clipped skin using a semi-occlusive dressing. The exposure periods were 3 minutes, 1 hour and 4 hours, respectively.

The 3-minute and 1-hour exposure resulted in well-defined erythema and slight oedema. The irritation had resolved within 72 hours or 7 days following exposure, respectively. A 4-hour exposure resulted in brown discolouration of the skin (a sign of superficial necrosis; due to which the maximum grade for erythema (grade 4) was assigned) at 48 and 72 hours and 7 days after exposure, severe oedema, reduced flexibility of the skin at 72 hours after exposure, fissuring of the skin at 7 days after exposure, and a bald skin with scaliness at 14 days after exposure. No evidence of full thickness destruction of the skin or scar tissue was observed during the observation period, indicating that no corrosion of the skin had occurred by dermal application of Sodium alkylnaphthalene sulfonate to the intact rabbit skin.

 

 

Eye irritation:

Older data from in vivo testing is available on Sodium akylnaphthalene sulfonate (low nonene) varied between irreversible effects and mildly irritating. To obtain more clarification and better comparison of eye irritant potency between Akylnaphthalene sulfonate (ANS) sodium salt, high nonene and low nonene, various in vitro BCOP studies were performed. This included testing ANS high nonene as 50% solution for 10 minutes resulting to an IVIS score of 85, and ANS low nonene pure powder, tested as 20% for 240 minutes, resulting to an IVIS 195.

However, as ANS is considered to be a surfactant, the BCOP studies were repeated following the advised protocol for surfactants, and tested as 10% solution for 10 minutes. This resulted to an IVIS of 49.1 (high nonene) and 43.3 (low nonene), indicating that the substance does not need to be classified as Cat.1 eye damage.

 

Results in vitro eye irritation studies:

ANS substance tested; BCOP exposure	IVIS results (*)
high nonene – 50% solution in water, 10 minutes exposure	85
low nonene solid powder – 20% solution in water, 250 min.	195
high nonene solid powder – 10% solution, 10 minutes	49.1
low nonene solid powder – 10% solution, 10 minutes	43.1

(*) IVIS score above 55 is considered predictive for Cat.1. eye damage.

 

The in viv oeye irritation study (WIL, 2014) was used as key study and was performed due to conflicting data from older animal studies andin vitrostudies from which no predictions could be made. The test was performed on ANS low nonene, as this showed the lowest IVIS score in the BCOP study performed under identical conditions. The results seen in this most recentin vivoeye irritation test on the sodium akylnaphthalene sulfonate (low nonene) showed irreversible effects in the eye of one of three rabbits tested.

 

There is no information on possible respiratory irritation.

Justification for classification or non-classification

Based on the in vivo skin irritation study in rabbits, Sodium alkylnaphthalene sulfonate should be classified for CLP as: skin irritant (Category 2) with H315: Causes skin irritation.

The results from the in vivo eye irritation study indicate that Sodium alkylnaphthalene sulfonate should be classified for CLP as having irreversible effects on the eyes (Category 1) with H318: Causes serious eye damage.

There is no information on possible respiratory irritation, so no conclusion can be made regarding STOT SE cat.3 classification for Respiratory tract irritation.