Terbium

Flammability

Link to relevant study record(s)

Reference

Endpoint:

flammable solids

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-09-16

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.10 (Flammability (Solids))

Deviations:

no

GLP compliance:

no

Key result

Test procedure:

burning time over 250 mm for metal powders or metal alloys

Burning time:

> 300 - < 600 s

Moisture (wt %):

0

A glow, but no visible flame, was observed which spread over the powder train. In the first experiment the

glow covered a distance of 8 cm in 6 min 30 sec. After additional 2 cm the glow extinguished after 15 min.

In a second experiment the glow covered a distance of 5 cm and extinguished after 8.

In a third experiment the glow covered a distance of 25 cm in 24 min.

In conclusion the sample could be ignited and the reaction spread over the powder train in more than 5

min and less than 10 min.

The substance has to be classified according to BAM classification and test methods regualtions

as flammable solid, devision 4.1 (packaging group III).

For reasons of precaution and safety the packaging group II is assigned.

Interpretation of results:

Category 2 (flammable solids) based on GHS criteria

Conclusions:

Under the conditions of the test described, the Rare Earth alloy could be ignited and reacted over the whole length of a sample in less than 10 minutes. The substance has to be classified according to BAM
classification and test methods regualtions as flammable solid, devision 4.1 (packaging group III). For reasons of precaution and safety the packaging group II is assigned.

Executive summary:

Under the conditions of the test described, the Rare Earth alloy could be ignited and reacted over the whole length of a sample in less than 10 minutes. The substance has to be classified according to BAM

classification and test methods regualtions as flammable solid, devision 4.1 (packaging group III). For reasons of precaution and safety the packaging group II is assigned.

Since the flammability depends on the Rare Earth content and the particle size of the alloy, the terbium alloys under consideration should also be classified.

Description of key information

Since the self-ignition temperature depends on the overall rare earth content and the particle size of the alloy, a representative alloy VD 687 was tested.

Under the conditions of the test described, the Rare Earth alloy could be ignited and reacted over the whole length of a sample in less than 10 minutes. The substance has to be classified according to BAM

classification and test methods regualtions as flammable solid, devision 4.1 (packaging group III). For reasons of precaution and safety the packaging group II is assigned.

Key value for chemical safety assessment

Flammability:

flammable

Additional information

The tested representative Rare Earth alloy VD 687 is not flammable in contact with water. The evolved quantity of gas was

120 ml/kg/h. Therefore no classification in class 4.3 according to BAM classification and test methods

regulation is required.

The tested representative Rare Earth alloy VACODYM VD 687 is a self-heating substance, class 4.2 and the packaging group II is assigned.

Since the self-heating behaviour depends on the Rare Earth content and the particle size of the alloy, the terbium alloys under consideration should also be classified.

Justification for classification or non-classification

Flammability:

A representative Rare Earth alloy was tested.

Under the conditions of the test described, the Rare Earth alloy could be ignited and reacted over the

whole length of a sample in less than 10 minutes. Therefore, the tested alloy has to be classified as flammable solid (

flammable solid 2, H228).

Since the flammability depends on the Rare Earth content and the particle size of the alloy, the terbium alloys under consideration should also be classified.

Elemental Terbium (in alloys) in mixture in a form of powder should therefore be classified as flammable solid (flammable solid 2, H228).

Flammability in contact with water:

A representative Rare Earth alloy was tested.

Under the conditions of the test the alloy (powder form) was not flammable in contact with water.

Self-heating:

The tested representative Rare Earth alloy VACODYM VD 687 is a self-heating substance, class 4.2 and the packaging group II is assigned.

Since the self-heating behaviour depends on the Rare Earth content and the particle size of the alloy, the terbium alloys under consideration should also be classified.