Hop, Humulus lupulus, ext.

Endpoint summary

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Oil-rich hop extract batch no. BI/YYF/1701

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Irritation / corrosion parameter:

% tissue viability

Value:

ca. 5.65

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Hop extract (Oil rich) is classfied as irritant to human skin

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Low oil hop extract batch no. 871008

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Irritation / corrosion parameter:

% tissue viability

Value:

ca. 3.39

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Justification for type of information:

An eye irritation study according to OECD test guideline 492 has been commissioned and an update will be made once results are available. The skin irritation studies performed on this substance, together with a long history of use as a food ingredient, indicate that a preliminary classification of eye irritation category 2 is appropriate, pending the results of the study planned.

Qualifier:

according to guideline

Guideline:

other: OECD 439

Version / remarks:

Weight of evidence to support study planned

GLP compliance:

yes (incl. QA statement)

Irritation parameter:

other: % tissue viability

Remarks:

Weight of evidence supporting study

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

An eye irritation study according to OECD test guideline 492 has been commissioned and an update will be made once results are available. The skin irritation studies performed on this substance, together with a long history of use as a food ingredient, indicate that a preliminary classification of eye irritation category 2 is appropriate, pending the results of the study planned.

Reference 2

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch no. 871 008

Irritation parameter:

other: Percentage of viability

Value:

ca. 28.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

Notes from study report:
Provided that the assay acceptance criteria are met:

• A test item is considered as “No Category”, i.e. not requiring a warning label in the European chemical classification systems for eye irritation or serious eye damage (UN GHS No Category), if the eye model viability after exposure and post-treatment incubation is >60%.

• If the mean percent tissue viability after exposure and post-exposure incubation is ≤60%, no prediction can be made.

The percentage of viability obtained with test item Hop Extract (Low Oil) was 28.432 %, therefore no prediction can be made. However, as described above (section 13), the tissues were exposed to the test item for 24 hours, and not the standard 6 hours, because of the difficulties faced when removing the test item from the tissue surfaces and this should be considered when reviewing the data presented in this report.

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

The test item was very sticky and so following the standard rinsing procedures, the testing lab was unable to fully remove the test item from the surfaces of the tissues at the end of the incubation time, meaning that the tissues were exposed to the tissue surfaces for longer than the time period stipulated in the test guideline procedure, and so this could potentially lead to a lower tissue viability result. This has been documented in the reports.

The test item is a naturally sticky resin and so the laboratory issues were reasonable. Inspection of the results, especially Graph 1 (see the attached results under "Attached background material") show that the positive control gave quite a low viability, and hop extract (test material) was in line with the positive control (neat methyl acetate; eye irritation Category 2). Together with weight of evidence from skin irritation studies, an eye irritation category 2 classification is reasonable.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)