(carboxylatomethyl)hexadecyldimethylammonium

Endpoint summary

Description of key information

Skin Irritation -

Mean value of three test data on a 35 active solution of the substance gave a value of 7.8% mean issue viability in the EpiDerm skin test (OECD 439).

Accoridng to the test protocol, a value of <=50% predicts Irritant GHS Cat 2.

Eye Irritation -

Under the conditions of the test, the sample eliicited an average in vitro score of 30.7.

The positive control elicited an average in vitro score of 46.0.

Under the decision cirteria of this test, these values fall within the 'No predictions can be made' category.

However, since the test sample was only 35% active and the value obtained suggested some effect, albeit not Cat 1 H318, it is likely that the undiluted substance may well have been eye corrosive and thus a precuationary classification of H319 Eye irritant Cat 2 has been applied.

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

GLP compliance:

yes

Specific details on test material used for the study:

Sample details not specified in the report but it is understood that the sample supplied was ColaTeric LAB, which is an aqueous solution of lauryl betaine in water at an active strength of 35%.

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: EpiDerm system - cultured

Vehicle:

unchanged (no vehicle)

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

30 microlitres of all articles.

Duration of treatment / exposure:

35 +/- 1 minute @ 37C and then placed in a steril hood until the 60 minute exposure period was reached.

Duration of post-treatment incubation (if applicable):

24 hours +/- 2 hours after washing.

Number of replicates:

Three

Irritation / corrosion parameter:

% tissue viability

Value:

7.8

Vehicle controls validity:

valid

Negative controls validity:

valid

Remarks:

Value is 2.287 and lies between the range of >=0.8 - <=2.8 as per OECD 439

Positive controls validity:

valid

Remarks:

Value is 7.4% which is <=20% as required by the method

Remarks on result:

positive indication of irritation

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Mean value of three test data gave a value of 7.8% mean issue viability in the EpiDerm skin test (OECD 439).
According to the test protocol, a value of <=50% predicts Irritant GHS Cat 2.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

ColaTeric LAB-70UP product was supplied by Colonial for this test.
The lot # was 55880C17. This product contains lauryl betaine (C12) at 35% active strength in water.

Vehicle:

physiological saline

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

The ColaTeric product was applied at 10% in saline. This infers that the strength of the active that was applied was 3.5%
A volume of 0.75ml was applied uniformly to the bovine cornea under conditions specified in the method.

Duration of treatment / exposure:

10 minutes, followed by a minimum of three washes.

Duration of post- treatment incubation (in vitro):

2 hours

Number of animals or in vitro replicates:

Three corneas were used per article.

Irritation parameter:

in vitro irritation score

Remarks:

Mean score for three readings

Value:

30.7

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

Mean in-vitro score = 46.0

Irritation parameter:

cornea opacity score

Remarks:

Mean score for three results

Value:

12

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

Mean opacity score = 27.3

Other effects / acceptance of results:

Acceptance criteria was met as being within 2 standard deviations of the current historical mean at the testing facility.

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

Under the conditions of the test, the sample eliicited an average in vitro score of 30.7.
The positive control elicited an average in vitro score of 46.0.
Under the decision cirteria of this test, these values fall within the 'No prdictions can be made' category, but is close to the level for th positive control and threfore a classification of Eye Irrit 2 is recommended.
Note that it was impossible to remove water and classification is basedon the 35% actives material as supplied.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Cetyl betaine (C16) and Lauryl betaine (C12) are very closely related chemical structures. The parent compound, betaine, is a naturally occurringN-trimethylated amino acid.

The individual betaines differ only in chain length. They are generally UVCB substances being manufactured from naturally occurring plant and animal sources.

 The Cosmetic Ingredient Review Expert Panel reviewed the product use, formulation and safety data of eleven alkyl betaines, as used in cosmetics. (Final report issued 2014-04-04)

The Panel concluded that the common core chemical structure, similar functions and concentrations in cosmetics, and the predicted physicochemical properties enabled grouping these ingredients and reading across the available toxicological data to support the safety assessment of each individual compound in the entire group.

Justification for classification or non-classification

Cetyl betaine is essentially the same molecule as lauryl betaine but with an extra C4 in the alkyl chain so it is likely that the toxicology of the two species will be very similar. Hence, it is assessed that the skin and eye irritancy response for cetyl would be similar to lauryl.