p-benzoquinone dioxime

Flammability

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

flammable solids

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Adequately documented guideline study performed, non-GLP. All relevant validity criteria were met. Testing conducted according to international transport and supply/use regulations and manual and criteria.

Qualifier:

according to guideline

Guideline:

UN Manual of Tests and Criteria: Test N.1 (Test method for readily combustible solids)

Version / remarks:

UN (2019). Recommendations on the Transport of Dangerous Goods Manual of Tests and Criteria (7th ed.), Geneva, United Nations

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.10 (Flammability (Solids))

Deviations:

no

GLP compliance:

no

Remarks:

Adequately documented guideline study performed, non-GLP. All relevant validity criteria were met. Testing conducted according to international transport and supply/use regulations and manual and criteria.

Key result

Test procedure:

burning rate test: preliminary screening test

Burning time:

ca. 9 s

Remarks on result:

other: In the initial trial, heat was applied with a flame for 2 minutes. The sample ignited in approximately 4 seconds and propagated 200 mm in 9 seconds. Further testing was deemed required.

Key result

Test procedure:

burning rate test with wetted zone

Burning time:

ca. 4 s

Remarks on result:

flame passes the wetted zone

Remarks:

When heat was applied with a flame the test item ignited in 2 seconds and propagated 100 mm with flame across the top of the train in 4 seconds and the flame passed the wetted zone.

Interpretation of results:

Category 1 (flammable solids) based on GHS criteria

Remarks:

EU & GHS criteria used in assessment

Conclusions:

The flammable solid properties of the test item was determined in a burning rate test consistent with UN Transport MTC Test N.1. The test item observed to have a mean burning time of 4 s and the flame passed the wetted zone. The test item was determined to be a flammable solid.

Executive summary:

The flammability of the solid test item was examined using a method consistent with the UN Transport of Dangerous Goods: Manual of Tests and Criteria: Test N.1 (7th ed., 2019) by measuring the burning rate of the test item. In a preliminary test, a rectangular mould (250 mm long x 20 mm wide x 10 mm high) was loosely filled with test item then inverted onto a cool impervious base plate to form an unbroken train. Typically, if a mould cannot be used, the sample is formed into the correct dimensions. A gas burner or a Nickel-Chromium wire is then placed at one end of the sample and ignition is attempted for a maximum of two minutes or 5 minutes for metal powders in order to determine the burning rate along a 200 mm distance. In the initial trial, heat was applied with a flame for 2 minutes. The sample ignited in approximately 4 seconds and propagated 200 mm in 9 seconds. Further testing was deemed required. In the definitive test, the test item was poured into a rectangular mould 200 mm long with a triangular cross section that has a height of 10 mm and a width of 20 mm at the base of the triangle. Pasty substances are formed into a rope with a cross section of approximately 100 mm^2. The test item was inverted onto a cool impervious base plate and a gas burner is placed at one end in an attempt to ignite the sample and when the pile has burned a distance of 80 mm, the burning time along a 100 mm distance is observed. If the powder is not a metal powder, a wetting agent is added approximately 25 mm beyond the timed zone in order to determine if the propagation of combustion will be inhibited by a wetting agent and to determine a packing group if the substance is determined to be a flammable solid. When heat was applied with a flame the test item ignited in 2 seconds and propagated 100 mm with flame across the top of the train in 4 seconds and the flame passed the wetted zone. The test item was therefore assigned into UN Transport: Flammable solids – division 4.1 packing group II. Applicant assessment indicates that: the classification of flammable solid met the UN Transport MTC N.1: Flammable solids - Division 4.1 packaging group II criteria. This is equivalent to the CLP Regulation (EC) 1272/2008: Flammable solids: category 1 criteria. Based on the wetted zone not stopping the fire for at least 4 minutes and the burning time being < 45 seconds or equivalent to > 2.2 mm/s burning rate. The test was performed on the test item as presented. The same form as supplied for transport and supply/use.

Reference 2

Endpoint:

substances / mixtures which in contact with water emit flammable gases

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the organic substance does not contain metals or metalloids and hence, the classification procedure does not need to be applied

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with section 1 of REACH Regulation (EC) No. 1907/2006 Annex XI, the does not need to be performed as based on assessment of the chemical structure flammability on contact with water properties are not to be expected and this is supported by experience in handling and use for the substance. According to ECHA Guidance on Information Requirements and Chemical Safety Assessment (Chapter R.7a: Endpoint Specific Guidance, R.7.1.10.8, July 2017), flammability on contact with water testing is scientifically unjustified.

Reference 3

Endpoint:

pyrophoric solids

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is known to be stable in contact with air at room temperature for prolonged periods of time (days) and hence, the classification procedure does not need to be applied

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with section 1 of REACH Regulation (EC) No. 1907/2006 Annex XI, the study does not need to be performed as based on assessment of the chemical structure pyrophoric properties are not to be expected and this is supported by experience in handling and use for the substance. According to ECHA Guidance on Information Requirements and Chemical Safety Assessment (Chapter R.7a: Endpoint Specific Guidance, R.7.1.10.5, July 2017), pyrophoricity testing is scientifically unjustified.

Description of key information

1a. Flammability: flammable solid ; experimentally determined burning rate > 2.2 mm/s and flame passing wetting zone, UN Transport MTC: Test N.1, 2021
2. Self-reactive properties: not a self-reactive substance, SADT > 75°C, for a 50 Kg Package, UN Transport MTC: Test H.4: Heat Accumulation Test, 2018
Supporting information:
1b. Flammability: flammable solid ; experimentally determined burning rate > 2.2 mm/s and not passing wetting zone, UN Transport MTC: Test N.1, 1991
Disregarded in favour of more strict hazard/risk assessment conclusion given in (1a) above.

Key value for chemical safety assessment

Flammability:

not classified

Additional information

Flammability:
In accordance with section 1.2 of REACH Regulation (EC) No. 1907/2006 Annex XI further study of flammability does not need to be completed based on weight of available evidence and structural assessment along with experience of handling and use.

The flammability of the solid test item was examined using a method consistent with the UN Transport of Dangerous Goods: Manual of Tests and Criteria: Test N.1 (7th ed., 2019) by measuring the burning rate of the test item. In a preliminary test, a rectangular mould (250 mm long x 20 mm wide x 10 mm high) was loosely filled with test item then inverted onto a cool impervious base plate to form an unbroken train. Typically, if a mould cannot be used, the sample is formed into the correct dimensions. A gas burner or a Nickel-Chromium wire is then placed at one end of the sample and ignition is attempted for a maximum of two minutes or 5 minutes for metal powders in order to determine the burning rate along a 200 mm distance. In the initial trial, heat was applied with a flame for 2 minutes. The sample ignited in approximately 4 seconds and propagated 200 mm in 9 seconds. Further testing was deemed required. In the definitive test, the test item was poured into a rectangular mould 200 mm long with a triangular cross section that has a height of 10 mm and a width of 20 mm at the base of the triangle. Pasty substances are formed into a rope with a cross section of approximately 100 mm^2. The test item was inverted onto a cool impervious base plate and a gas burner is placed at one end in an attempt to ignite the sample and when the pile has burned a distance of 80 mm, the burning time along a 100 mm distance is observed. If the powder is not a metal powder, a wetting agent is added approximately 25 mm beyond the timed zone in order to determine if the propagation of combustion will be inhibited by a wetting agent and to determine a packing group if the substance is determined to be a flammable solid. When heat was applied with a flame the test item ignited in 2 seconds and propagated 100 mm with flame across the top of the train in 4 seconds and the flame passed the wetted zone. The test item was therefore assigned into UN Transport: Flammable solids – division 4.1 packing group II. Applicant assessment indicates that: the classification of flammable solid met the UN Transport MTC N.1: Flammable solids - Division 4.1 packaging group II criteria. This is equivalent to the CLP Regulation (EC) 1272/2008: Flammable solids: category 1 criteria. Based on the wetted zone not stopping the fire for at least 4 minutes and the burning time being < 45 seconds or equivalent to > 2.2 mm/s burning rate. The test was performed on the test item as presented. The same form as supplied for transport and supply/use.

Other measures of flammability include pyrophoricity and flammability on contact with water. These can be considered not a concern for the substance and testing waived if consideration of the structure and experience in handling and use show that no effects are envisaged. Such a screening procedure represents an intelligent testing strategy for flammability. If applied correctly then only liquid substances for which it is suspected will give a positive result in either the pyrophoric properties or flammability on contact with water tests need to be tested.

A review of the structure suggests that there are no chemical groups present that would imply pyrophoric properties or flammability on contact with water. A review of handling and used implies no pyrophoric properties or flammability on contact with water. Based on the absence of structural alerts and experience in handling and use negative results are predicted for pyrophoric properties and flammability of contact with water. Based on the preliminary screening tests for solids flammability, the substance is not considered to be flammable.

It is noted by the applicant that from ECHA Guidance on the CLP Criteria (2017) section 2.7.3: ‘Explosives, organic peroxides, self-reactive substances and mixtures as well as pyrophoric or oxidising solids should not be considered for classification as flammable solids since flammability is an intrinsic hazard in these classes’. However, it should be noted that the explosivity hazard of the test item is specific to ‘heating under confinement’ and/or based on presented data when suitably packaged, as a result of resultant heat flux within available external bonfire tests conducted being sufficient to classify under GHS Explosivity category 1.4 compatibility group C.

Where as substance is classified as GHS ‘Explosive’ category 1 and therefore not classified as GHS ‘flammable solid’ per se, (see: ECHA Guidance on the CLP Criteria (2017) section 2.1.3), regardless : all available information is presented to protect industrial and professional users during transport/storage that the test item may cause or will contribute to fire.

References:
1. UN Transport of Dangerous Goods Manual of Tests and Criteria, Seventh Edition (2019)
2. Bretherick (1999) Bretherick’s Handbook of Chemical Reactive Hazards: An Indexed Guide to Published Data, 6th Edition (2 volume set).
3. ECHA Guidance on Information Requirements and Chemical Safety Assessment (Chapter R.7a: Endpoint Specific Guidance, R.7.1.10, July 2017)
4. REACH Regulation (EC) 1907/2006, Annex XI, section 1
5. CLP Regulation (EC) 1272/2008, Annex I, section 2.6 and 2.7
6. ECHA Guidance on Application on the CLP Criteria, section 2.6 and 2.7 (v4.1, July 2017)

 

Self-heating properties (as a sub-classification criteria of flammability):
In accordance with REACH Regulation (EC) No. 1907/2006 Annex VII, column 2 section 7.12 the study for self-ignition temperature – and sub-classification: self-heating substances (under CLP Regulation (EC) 1272/2008: Annex 1, section 2.11.1.1) and which is also covered under REACH Regulation (EC) No. 1907/2006 Annex VII, column 2 section 7.10: flammability: the test does not need to be conducted if the substance is explosive. The test for self-heating properties does not need to be conducted as it is not scientifically necessary. Instead, testing for explosivity, self-reactive properties and flammability is presented. According to ECHA Guidance on Information Requirements and Chemical Safety Assessment (Chapter R.7a: Endpoint Specific Guidance, R.7.1.10.7, July 2017) the study does not need to be conducted.

References:
1. UN Transport of Dangerous Goods Manual of Tests and Criteria, Seventh Edition (2019)
2. ECHA Guidance on Information Requirements and Chemical Safety Assessment (Chapter R.7a: Endpoint Specific Guidance, R.7.1.10.7, July 2017). With additional references to sections R.7.1.10 – flammability and R.7.1.2.1 – self-ignition temperature.
3. CLP Regulation (EC) 1272/2008, Annex I, section 2.11
4. ECHA Guidance on Application on the CLP Criteria, section 2.11 (v5.0, July 2017)

Justification for classification or non-classification

The substance meets classification criteria under Regulation (EC) No 1272/2008 for flammable solids: category 1: H228: Flammable solid
However: the substance also meets the classification criteria under Regulation (EC) No 1272/2008 for explosives Division 1.4 : H204: Fire or projection hazard. Furthermore, if inappropriately packaged/stored it could result in explosive hazards relevant ‘from heating under confinement’. Explosivity has a higher order of precedence for hazard than Flammable Solids. Therefore the substance is not classified in the Flammable Solid hazard category.

See ‘Explosivity’ section for further information.

The substance does not meet classification criteria under Regulation (EC) No 1272/2008 for self-reactive properties.