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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Skin irritation / corrosion

Currently viewing:

Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Reference substance name:
Hop, Humulus lupulus, ext., isomerized, potassium salt
EC Number:
305-203-0
EC Name:
Hop, Humulus lupulus, ext., isomerized, potassium salt
Cas Number:
94349-84-5
Test material form:
solid
Remarks:
Resinous solid. Becomes flowable above 60 oC.
Specific details on test material used for the study:
Batch no. EXP 7

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
non-transformed keratinocytes
Vehicle:
unchanged (no vehicle)

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
Viability measured after 3 minutes
Value:
ca. 40.3
Positive controls validity:
valid
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
Tissue viability measured after 1 hour
Value:
ca. 28.1
Positive controls validity:
valid

Applicant's summary and conclusion

Interpretation of results:
Category 1 (corrosive) based on GHS criteria
Conclusions:
Notes from study report: "After 3 min and 1h exposure on the surface of EpiDermTM reconstructed human epidermis, the viability of the tissues was assessed and compared to a negative control.
The percentage of viability obtained was 40.3% after 3 min and 28.1% after 1h and therefore:
Potassium Iso-Alpha Resin was classified as Corrosive, optional sub-category 1B/1C to human skin."

Since tetrahydroisoalpha acids are simply hydrogenated, with two side chain C=C double bonds converted to CH-CH, then it is appropriate to read across the classification from iso-alpha acids.