[No public or meaningful name is available]

Endpoint summary

Description of key information

The studies performed on analogues (hydrolysed proteins obtained from different animal and vegetable sources) were prepared mostly for the safety assessment for cosmetic ingredients. Case studies on human sensitization show that the peptides with MW > 3.5 kDa might have sensitizing potential while for the peptides of MW< kDa this potential is very low and are considered safe for use on skin.

In order to cross-link IgE in sensitised individuals, a protein needs to have a minimum size which is assumed to be in the order of 3 kDa. It can be argued that proteins of this size are also unlikely to induce clinically relevant (type I) sensitisation. The CIR Expert Panel concluded that wheat protein hydrolysate is safe for use in cosmetics when formulated to restrict peptides to a weight average MW of 3.5 kDa or less (CIR (2014)).

The SCCS considers the use of hydrolysed wheat proteins safe for consumers in cosmetic products, provided that the maximum molecular weight average of the peptides in hydrolysates is 3,5 kDa.

All peptides in the registered substance have the MW< 1 kDa so are not expected to cause any skin sensitization.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

The provided key study was performed on the protein hydrolysate derived from wheat and considered a relevant source for the read-across assessment of the properties of corn gluten hydrolysate (analogue approach).
All protein hydrolysates can be regarded as analogues with similar properties on basis of having common precursors (proteins) and common breakdown products (amino acids, peptides) through physical and/or biological processes which result in structurally similar degradation products (similarity through biotransformation).

The animal and vegetable cells are formed mainly by proteins, which constitute more than the half of the dry weight of the cell. These components and their degradation products are constantly present in the animal and human diet and in the environment.

After ingestion, proteins are hydrolyzed in the gastrointestinal tract by proteolytic enzymes derived from the pancreas resulting in the release of dipeptides, tripeptides and free amino acids. Digestion is further enhanced by proteases, such as aminopeptidase N, that are located in the plasma membrane of the intestinal cells. Single amino acids, as well as di- and tripeptides, are transported into the intestinal cells from the lumen and subsequently released into the blood for absorption by other tissues. The final digestion products are then used by the cells for the biosynthesis of new specific proteins, or they can then undergo further amino acid catabolism, where they are utilized as an energy source.

Proteins derived from different sources has different amino acid profiles. The hydrolysates also have different compositions depending on the manufacturing process and hydrolysing agents used. Differences also include oligopeptides and peptides chains length and structure. While these differences might be meaningful when considering the use of protein hydrolysates as food supplements and their beneficial impact on health condition, they do not make significant difference for the toxicological or ecotoxicological profiles of particular hydrolysates. All proteins, regardless their source and structure, are in the end subject to the same degradation processes and metabolic pathways.

Reason / purpose for cross-reference:

read-across source

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0,5 ml of 50% solution

No. with + reactions:

1

Total no. in group:

20

Clinical observations:

slight patchy erythema

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0,5 ml of 50% solution

No. with + reactions:

0

Total no. in group:

20

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0,5 ml of 50% solution

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

slight patchy erythema

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0,5 ml of 50% solution

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

slight patchy erythema

Interpretation of results:

GHS criteria not met

Conclusions:

The subatnce is not classified as sensitizingto skin

Executive summary:

The key study was performed on the protein hydrolysate derived from pig trachea and considered a relevant source for the read-across assessment of the properties of corn gluten hydrolysate (analogue approach).

All protein hydrolysates can be regarded as analogues with similar properties on basis of having common precursors (proteins) and common breakdown products (amino acids, peptides) through physical and/or biological processes which result in structurally similar degradation products (similarity through biotransformation).

The animal and vegetable cells are formed mainly by proteins, which constitute more than the half of the dry weight of the cell. These components and their degradation products are constantly present in the animal and human diet and in the environment.

The lack of sensitizing properties of protein hydrolysate shown in the study is indeed in line with expectations. Protein hydrolysates are present in various cosmetics producsc and have been assessed for their safety for skin contact

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)