Fatty acids, tall-oil, reaction products with acrylic acid

Endpoint summary

Description of key information

In vitro skin irritation (OECD439): irritating (reconstructed human epidermis)

In vivo eye irritation (OECD405): corrosive (rabbit)

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From Jan 21 to Jan 24, 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

Commercially available Epi-200-SIT-Kit.
Epi-200 tissues were procured from MatTek In Vitro Life Science Laboratories, Bratislava.

Control samples:

yes, concurrent negative control

Amount/concentration applied:

30 μL of liquid test item

Duration of treatment / exposure:

1 hour

Duration of post-treatment incubation (if applicable):

18 hours

Number of replicates:

2 replicates for each of the three tissues.

Irritation / corrosion parameter:

other: % formazan production compared to negative control

Run / experiment:

Mean of 3 tissues

Value:

3.8

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

2.9%

Other effects / acceptance of results:

The variation within replicates (RSD) of test item was 35%. This high value is due to mathematical reasons. The absorption values of the test itme are vary small; therefore the variation within the replicates leads to a high RSD. This can eb seen as uncritical because the test item showed very clearly irritating results and the value is well below the threshold for irritation (50%). Values for negative and positive controls were within the range of historical data of the test facility. Therefore, the experiment is considered valid.

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

The test item is considered irritant

Executive summary:

Three tissues of the human skin model EpiDerm ^TM were treated with test item for 60 minutes. 30 μL of the liquid test item (using a nylon mesh) were applied to each tissue and spread to match the tissue size. DPBS-buffer was used as negative control, 5% SDS-solution was used as positive control. after treatment with the negative control, the absorbance values were within the required acceptability criterion of 1.0<mean OD<2.5. The positive control showed clear irritating effects. Variation within tissues of the negative and positive controls was acceptable (<18%). after the treatment with test item, the relative absorbance values were reduced to 3.8%. This value is well below the threshold for irritation potential (50%). Therefore, test item was considered as irritant in the Human Skin Model Test. According to the UN GHS system for skin irritation, the substance is considered classified as "Skin Irritant Cat. 2".

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:

1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

yes

Remarks:

6 animals instead of 3

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: S&S Associates
- Age at study initiation: young adult
- Weight at study initiation: 2.3-3.5 kg
- Housing: Housed individually in stainless steel pens with raised flooring suspended over drip pans lined with absorbent paper bedding.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: No data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.3-23.8
- Humidity (%): 40-60
- Air changes (per hr): conditioned room
- Photoperiod (hrs dark / hrs light): 12 / 12

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml
- Concentration (if solution): undiluted (100%)

Duration of treatment / exposure:

24 hours

Observation period (in vivo):

1 hour after installation, and 24, 48 and 72 hours after, and thereafter daily for 21 days

Number of animals or in vitro replicates:

6

Details on study design:

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

SCORING SYSTEM: The numerical scorings recorded were made in compliance with OECD guideline 405, 1992, scoring ocular lesions (corneal, iridic and conjunctival irritation, and discharge).

TOOL USED TO ASSESS SCORE: No data

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

6 animals

Time point:

24 h

Score:

ca. 0.16

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: 3 animals exhibited fibrovascular connective tissue (an indication of corrosion)

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

6 animals

Time point:

48 h

Score:

ca. 0.5

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: 3 animals exhibited fibrovascular connective tissue (an indication of corrosion)

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

6 animals

Time point:

72 h

Score:

ca. 0.66

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Remarks on result:

other: 3 animals exhibited fibrovascular connective tissue (an indication of corrosion)

Irritation parameter:

iris score

Basis:

mean

Remarks:

6 animals

Time point:

24 h

Score:

ca. 0.16

Max. score:

2

Reversibility:

fully reversible within: 21 days

Irritation parameter:

iris score

Basis:

mean

Remarks:

6 animals

Time point:

48 h

Score:

ca. 0.16

Max. score:

2

Reversibility:

fully reversible within: 21 days

Irritation parameter:

iris score

Basis:

mean

Remarks:

6 animals

Time point:

72 h

Score:

ca. 0.16

Max. score:

2

Reversibility:

fully reversible within: 21 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

6 animals

Time point:

24 h

Score:

ca. 2.66

Max. score:

3

Reversibility:

fully reversible within: 21 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

6 animals

Time point:

48 h

Score:

ca. 2

Max. score:

3

Reversibility:

fully reversible within: 21 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

6 animals

Time point:

72 h

Score:

ca. 1.66

Max. score:

3

Reversibility:

fully reversible within: 21 days

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

6 animals

Time point:

24 h

Score:

ca. 2.66

Max. score:

4

Reversibility:

fully reversible within: 21 days

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

6 animals

Time point:

48 h

Score:

ca. 2.16

Max. score:

4

Reversibility:

fully reversible within: 21 days

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

6 animals

Time point:

72 h

Score:

ca. 2.16

Max. score:

4

Reversibility:

fully reversible within: 21 days

Irritant / corrosive response data:

Immediately after dosing, all 6 test animals displayed pawing and rubbing of the test eye. 24 hours after dosing, 1 test animal displayed corneal irritation with scattered or diffuse areas of opacity but details of iris still clearly visible. By 48 hours, 3 more animals developed this type of corneal opacity. By Day 7, 2 of these 3 animals exhibited fibrovascular connective tissue (an indication of corrosion) and a third test animal developed it on Day 10. The remaining 3 test animals showed complete recovery or significant improvement by Day 21.
During the 72-hour observation period, 3 test animals exhibited markedly deepened folds, congestion, swelling, moderate circumcorneal injection with iris still reacting to light. On Day 7, a fourth animal developed the same type of irritation and one animal recovered from the irritation.
One hour after dosing, all 6 test animals displayed conjunctivae irritation. This irritation ranged from some vessels definitely injected to diffuse, crimson red, individual vessels not easily discernible. 5 of the 6 test animals' irritation became more severe by 24 hours. Complete recovery or slight recovery was observed in 3 of the animals by Day 21.
One hour after dosing, all 6 test animals exhibited chemosis, ranging from swelling with lids about half closed to swelling with lids more than half closed. This swelling improved slightly by 24 hours, in 4 of the 6 test animals. Recovery was observed in 3 of the test animals by Day 10.
One hour after dosing, 2 of the 6 test animals displayed slight discharge (any amount different from normal). At 24 hours after dosing, another 3 test animals exhibited discharge ranging from any amount different than normal to discharge with moistening of the lids and hairs, and considerable area around the eye. At Day 7, hair loss around the test eye was observed in one test animal. Additionally, 2 test animals developed a bloody discharge by Day 10. Complete recovery was observed in 3 of the 6 test animals by Day 21.

Other effects:

Not relevant

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

When tested as specified, the submitted test substance, Diacid 1550 Tall Oil Fatty Acid, induced eye irritation in all 6 test rabbits. The average mean scores calculated from the numerical values given to the eye irritation observed at the 24, 48, and 72 hour examinations of the 6 rabbits were 0.16, 0.5, and 0.66 for corneal irritation, and 0.16 for iris irritation, 2.66, 2.0, and 1.66 for conjunctivae (redness) irritation, and 2.66, 2.16, and 2.16 for chemosis. Fibrovascular connective tissue (an indication of corrosion) was observed in 2 of the test animals by Day 7 and a third by Day 10. Complete recovery or slight recovery was observed in the remaining 3 test animals by Day 21. Based on these results and according to the EU criteria outlined in Annex VI of 67/548/EEC and Annex I of 1272/2008/EC (CLP/EU-GHS), Diacid 1550 Tall Oil Fatty Acid has to be classified and labeled as corrosive to the eyes.

Executive summary:

The primary eye irritation potential of Diacid 1550 Tall Oil Fatty Acid was investigated according to OECD test guideline no. 405, 1992. The test item was applied by instillation of 0.1 ml into one eye of each of 6 young adult New Zealand White rabbits for 24 hours. Scoring of irritation effects was performed approx. 1, 24, 48 and 72 hours after test item instillation, in compliance with OECD 405, scoring ocular lesions (corneal, iridic and conjunctival irritation, and discharge). Observation period was 21 days. When tested as specified, the submitted test substance, Diacid 1550 Tall Oil Fatty Acid, induced eye irritation in all 6 test rabbits. The average mean scores calculated from the numerical values given to the eye irritation observed at the 24, 48, and 72 hour examinations of the 6 rabbits were 0.16, 0.5, and 0.66 for corneal irritation, and 0.16 for iris irritation, 2.66, 2.0, and 1.66 for conjunctivae (redness) irritation, and 2.66, 2.16, and 2.16 for chemosis. Fibrovascular connective tissue (an indication of corrosion) was observed in 2 of the test animals by Day 7 and a third by Day 10. Complete recovery or slight recovery was observed in the remaining 3 test animals by Day 21. Based on these results and according to the EU criteria outlined in Annex VI of 67/548/EEC and Annex I of 1272/2008/EC (CLP/EU-GHS), Diacid 1550 Tall Oil Fatty Acid has to be classified and labeled as corrosive to the eyes.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Six skin irritation studies have been performed with Diacid 1550 and a summary of the available studiesis presented in the table below. A substance is considered to be corrosive if it produces destruction of skin tissue in at least one tested animal. A substance is considered to be irritating to skin if a substance produces an erythema/eschar or oedema score of ≥2.3 to ≤4.0 in at least 2 of 3 animals.

Study title, author, laboratory, year	% Diacid	GLP	Used guideline	Report conclusion	EU classification (DSD and CLP)
Acute toxicity studies with Diacid 1550, Hintz, C. and Kretchmar, B., Industrial Biotest Laboratories, 1973 (report number: 601-04128)	70	No (prior to GLP)	Not specified. In accordance with Draize et al (1944). 24 hr exposure. Only 24 and 72 hr scored. Not to be used for classification.	Moderately irritating (based on primary irritation index of 5), however, superficial burns observed in 2 of 6 animals.	Corrosive after 24 hr exposure based on superficial chemical burns observed in 2 of 6 animals.
Diacid 1550: Acute dermal irritation test in the rabbit, Sanders, A., Safepharm Laboratories Ltd. , 1997 (report number: 1118/001	70	Yes	Acute dermal irritation test according to OECD404	Not irritating according to DSD / moderately irritating according to primary irritation index	Not irritating
Eye irritation and skin irritation on Diacid 1550 Tall Oil Fatty Acid (C21 Dicarboxylic Fatty Acid), Breheny, J. and Tong, C.C., SGS US Testing Companies Inc., 1997 (report number: 202998-02)	70	Yes	Primary skin irritation test according to EPA 560/6-82-001 and EPA540/9-82-025	Irritating	Corrosive - crust formation (indication of corrosion) observed in 3 of 6 animals
OECD Skin and eye irritation test on Diacid 1550 Tall Oil Fatty Acid (C21 Dicarboxylic Fatty Acid), Breheny, J. and Tong, C.C., SGS US Testing Companies Inc., 1997 (report number: 202998-01)	70	Yes	Acute dermal irritation test according to OECD404 (testing up to 72 hr)	Corrosive	Corrosive - crust formation (indication of corrosion) observed in one animal after 72 hr, and in the remaining animals after 7 days.
Determination of skin corrosion potential of DIACID 1550 in the Human Skin Model Test following OECD Guideline 431 and EU-Method B.40 BIS, I Andres I. LAUS GmbH, 2013 (report number:13101001G820)	70	Yes	OECD 431	Not corrosive	Further evaluation required to determine irritation potential
Determination of skin irritation potential of DIACID 1550 in the Human Skin Model Test following EU-Method B.46 resp. OECD 439 , Andres I. LAUS GmbH, 2014 (report number: 13101001G840)	70	Yes	OECD 439	Irritant	Irritant

The animal studies report borderline cases of corrosion under occlusive conditions (Tong, 1997; Breheny, 1997; Hintz and Kretchmar, 1973) and the one semi-occlusive study (Sanders 1997) indicates the substance is non-irritating. As the majority of the studies demonstrated corrosion in skin, the substance was initially classified as CLP Skin Corrosion Category 1C in the 2013 REACH Chemical Safety Report.

 

Recently, two in vitro studies for skin corrosion/skin irritation were conducted. The first in vitro skin corrosion study (Andres, 2013) reported the substance not to be corrosive to the skin under the test conditions; however, further testing for potential irritation was established to be required for CLP classification. The results of a follow-up in vitro skin irritation study (Andres, 2014) that was conducted for CLP classification purposes indicated that the substance is an irritant under the test conditions.

 

In order to determine skin corrosion/skin irritation classification of Diacid1550, results of the new in vitro tests and relevant in vivo animal data have been evaluated with the understanding that results from well-conducted animal studies have precedence over in vitro data (ECHA, 2015 – Guidance on the application of CLP Criteria, Version 4.1 – June 2015). However, ECHA CLP Guidance indicates that human skin is less sensitive than rabbit skin (ECHA, 2015 – Guidance on the application of CLP Criteria, Version 4.1 – June 2015) and occlusive testing conditions may be considered to be overly conservative. Based on the results of the in vitro studies indicating the substance is irritating and the in vivo non-irritating result in the semi-occlusive study, Diacid 1550 may be classified as CLP Skin Irritation Category 2.

 

For eye irritation, two studies have been performed to determine eye irritation of Diacid 1550. The key study was performed in accordance with OECD 405, and the supporting study was performed in accordance with EPA-guidelines. A summary of these studies is provided below.

Study title, author, laboratory, year	% Diacid	GLP	Used guideline	Report conclusion	EU classification
OECD Skin and eye irritation test on Diacid 1550 Tall Oil Fatty Acid (C21 Dicarboxylic Fatty Acid), Breheny, J. and Tong, C.C., SGS US Testing Companies Inc., 1997 (report number: 202998-01)	70	Yes	Acute eye irritation/corrosion test according to OECD405	Corrosive (based on fibrovascular connective tissue in two of the six animals)	Corrosive
Eye irritation and skin irritation on Diacid 1550 Tall Oil Fatty Acid (C21 Dicarboxylic Fatty Acid), Breheny, J. and Tong, C.C., SGS US Testing Companies Inc., 1997 (report number: 202998-02)	70	Yes	Eye irritation test according to EPA 560/6-82-001 and EPA540/9-82-025	Corrosive (based on fibrovascular connective tissue in two of the six animals)	Corrosive
Acute toxicity studies with Diacid 1550, Hintz, C. and Kretchmar, B., Industrial Biotest Laboratories, 1973 (report number: 601-04128)	70	No (prior to GLP)	No guideline specified.	Severely irritating	-

Both studies show fibrovascular connective tissue in two of the six animals, which is an indication of corrosion. Based on these results, Diacid 1550 may be classified as CLP Eye Damage Category 1.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

Based on the available information, Diacid 1550 should be classified as skin irritant and corrosive for the eyes, in accordance with the criteria outlined in Annex VI of 67/548/EEC and Annex I of 1272/2002/EC.