Subtilisin

Flammability

Link to relevant study record(s)

Reference

Endpoint:

flammable solids

Remarks:

freeze-dried enzymes

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

03 September 2019 - 08 November 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The data has been generated for a study with cellulase, but similar results are expected for XXXX enzyme.

Qualifier:

according to guideline

Guideline:

EU Method A.10 (Flammability (Solids))

Version / remarks:

30 May 2008

GLP compliance:

yes (incl. QA statement)

Key result

Test procedure:

burning rate test over 100 mm length

Remarks on result:

substance does not ignite and propagate combustion either by burning with flame or smouldering along 200 mm of the powder train within the 2 minutes test period

The pile ignited briefly with an orange flame which self-extinguished without propagating combustion.

Since the test item did not propagate combustion along 200 mm of the powder train within the four minutes test period, the test item is not considered to be highly flammable and no further testing was required.

Interpretation of results:

GHS criteria not met

Conclusions:

The test item has been determined to be not highly flammable as it did not propagate combustion over the 200 mm of the preliminary screening test.

Executive summary:

Cellulase, batch PPC31776 (freeze-dried aliquot) has been determined to be not highly flammable, using a procedure designed to be compatible with Method A.10 Flammability (Solids) of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Description of key information

Cellulase was freeze-dried and tested for flammability. The test showed that cellulase is not flammable.

Most of the enzymes are produced by fermentation, typically in solution. After the fermentation, enzymes are recovered as enzyme concentrate in a liquid form and further formulated as liquid products or granules.

The substance in contact with water is not considered to be highly flammable according to Regulation (EC) No 440/2008.

 

Based on this data, other enzymes are also expected to be Non-flammable (Not Classified).

Key value for chemical safety assessment

Flammability:

not classified

Additional information

Enzymes are globular proteins produced by fermentation i.e. typically in solution. After the fermentation, enzymes are recovered as enzyme concentrate in a liquid form and further formulated as liquid products or granules. The production process is described in Section 1.2 of IUCLID in more details. Decades of experience in production, handling and use of enzymes show that the substance does not react with water (e.g. the substance is manufactured with water or/and washed with water). The substance is soluble (see Section 4.8 of IUCLID) and stable in water. Therefore, the substance in contact with water is not considered to be highly flammable according to Regulation (EC) No 440/2008. Under REACH, enzymes are defined as enzyme concentrate, dry matter (1). As dry matter, proteins in general are not considered to be highly flammable according to Regulation (EC) No 440/2008. This is supported by the chemical structure of the proteins. Proteins contain reactive groups such as hydroxyl, carboxylic acid, amines, thiols groups etc. During combustion, carboxylic acid groups may go through decarboxylation and hydroxyl groups may be released as water vapor (3). The carboxylic acid may also promote char formation (2, 3). Proteins also contain nitrogen and sulfur which form a disulfide bond helping in contributing to its non-inherent flammability (2, 3). These properties have in fact led to the use of proteins as flame retardants (2, 3). Additionally, several proteins have already been tested using recognized method under REACH and CLP (e.g. UN Test N.1) and found not to be highly flammable according to Regulation (EC) No 440/2008, e.g. Protein hydrolyzates, rice bran (EC number: 305-224-5), Protein hydrolyzates, animal (EC number: 309-203-1), Insulin DesB30 (EC number: 944-550-8).

References: 1. Guidance for identification and naming of substances under REACH and CLP, Version 2.1.

2. https://onlinelibrary.wiley.com/doi/full/10.1002/fam.2386

3. https://patents.google.com/patent/WO2000029662A1/en Based on above weight of evidence, a study for flammability is deemed unnecessary.

Justification for classification or non-classification

Not classified