Registration Dossier

Physical & Chemical properties

Flammability

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Flammability:
highly flammable

Additional information

Magnesium powder (pyrophoric)(Index no.: 012-001-00-3)is legally classified in accordance with Directive 67/548/EEC Annex I and Regulation (EC) 1272/2008 Annex VI as pyrophoric (H250) and flammable in contact with water (H260). However, there is not a reliable basis or study available upon which this classification could either be verified or rebutted.

Furthermore, Magnesium powder or turnings(Index no.: 012-002-00-9) arelegally classified in accordance with Directive 67/548/EEC Annex I and Regulation (EC) 1272/2008 Annex VI as self-heating (H252), flammable (H228) and flammable in contact with water (H261). However, there is not a reliable basis or study available upon which this classification could either be verified or rebutted.

As the harmonized classifications do notcorrespond withlong-time experience in industrial manufacture and handling of magnesium powder, an extensive program has been conducted to test the following hazard properties of different grades of magnesium powder. The selected grades are representative of the magnesium powders imported, made and marketed in the EU, differ in particle size and include a powder with the respective smallest and largest particle size. All results of the testing program are reported in the table and can be summarized as follows.

Table: Test results and concludions for classification & labelling in accordance to Regulation (EC) 1272/2008

D50of tested powder [µm]

39.3

58.6

122.2

668.3

995.2

1,900

2,650

2,650 µm

D1of tested powder [µm]

 

 

 

 

 

 

> 500

< 500

Flam. Solid

Not tested

Cat. 1, H228)1

Not tested

Not tested

No

Not tested

Not tested

Not tested

Pyrophoric Solid

No

No

Not tested

No

Not tested

Not tested

Not tested

Not tested

Self-heating substance

No

No

Not tested

No

Not tested

Not tested

Not tested

Not tested

Emits in contact with water flammable gases

(Water React. Flam. Gas)

Cat. 2, H261

Cat. 2, H261

Cat. 3, H261

Cat. 3, H261

Cat. 3, H261

No

No

Cat. 3,
H261

UN PG based on test results

II

II

II

II

III

-

-

III

)1D50 52.7 µm

(i)             Flammability in contact with air with 3 different grades of Mg powder (UN-test N.2)

Three magnesium powders ranging in particle size (i.e., D50s range from 39.3 µm to 668.3 µm) do not meet the criteria for classification as "Pyrophoric solid" in accordance withRegulation (EC) 1272/2008. It is concluded that magnesium powders with a D50 above 40 µm are non-flammable in contact with air. Therefore, massive magnesium is also considered non-flammable in contact with air.

(ii)           Self-heating with 3 different grades of Mg powder (UN-test N.4)

Three magnesium powders ranging in particle size (i.e., D50s range from 39.3 µm to 668.3 µm) do not meet the criteria for classification as "self-heating substance" in accordance withRegulation (EC) 1272/2008. It is concluded that magnesium powders with a D50 above 40 µm mm are not self-heating. Therefore, massive magnesium is also not considered to be self-heating.

(iii)          Flammability with 2 different grades of Mg powder (UN-test N.1)

The flammability of 2 different grades of magnesium powder (i.e., D50 of 52.7 µm and a D50 of 995.2 µm) were tested with the following results:

- Magnesium powder with a D50 of 52.7 µm tested flammable Cat 1 (Flam. Sol. 1, H228) in accordance with Regulation (EC) 1272/2008

- Magnesium powder with a D50 of 995.2 µm tested non-flammable in accordance with Regulation (EC) 1272/2008.

 

(iv)         Flammability in contact with water with 7 different grades of Mg powder (UN-test N.5)

The flammability in contact with water of 7 different magnesium-powder grades (D50s range form 39.3 µm to 2,650 µm) were tested with the following results: 

- Magnesium powders with a D50 below 100 µm, i.e. powders with D50s of 39.3 µm and 58.6 µm, respectively, tested flammable in contact with water Cat 2 (Water-react. 2, H261 in accordance with Regulation (EC) 1272/2008; UN transport regulation packing group II).

- Magnesium powders with a D50 above 100 µm and below 2,000 µm, i.e. powders with D50s of 122.2 µm, 668.3 µm and 995.2 µm, respectively, tested flammable in contact with water Cat 3 (Water-react. 3, H261 in accordance with Regulation (EC) 1272/2008; UN transport regulation packing group III).

- Magnesium powders with a D50 ≥ 2,000 µm, i.e., powders with D50s of 1,900 µm and 2,650 µm, respectively, tested non-flammable in contact with water in accordance with Regulation (EC) 1272/2008 and UN transport regulation (i.e., maximum rate of gas emission is < 1 l/(kg*h)). However, according to the UN transport regulation; powders with 1% of particles being smaller than 500 µm should be ground. Thus, the powder with a D50 of 2,650 µm with 8.4% of particles being smaller than 500 µm was ground and the ground material tested flammable in contact with water Cat 3 (Water-react. 3, H261 in accordance with Regulation (EC) 1272/2008; UN transport regulation packing group III) since the maximum rate of gas emission is > 1 l/(kg*h) but < 20 l/(kg*h). Thus, the test results indicate that powders with a D50 ≥ 2,000 µm and a D1 > 500 µm are non-flammable in contact with water whereas powders with a D50 ≥ 2,000 µm but a D1 ≤ 500 µm are flammable in contact with water Cat 3 (Water-react. 3, H261 in accordance with Regulation (EC) 1272/2008; UN transport regulation packing group III).

Furthermore, magnesium powders with a D50 ≥ 40 µm and < 200 µm are water-reactive Cat. 2, since the maximum rate of gas emission is > 20 l/(kg*h) but < 10 l/(kg*min).

These results indicate that the differentiation between the two existing CLP Annex VI entries “magnesium powder (pyrophoric), Index # 012-001-00-3, EC # 231-104-6, CAS # 7439-95-4” and “magnesium powder or turnings, Index # 012-002-00-9, EC # 231-104-6, CAS # -” is arbitrary for magnesium powders that are imported, made and marketed in the EU since,

- all tested representative magnesium powders with a D50 ≥ 40 µm are neither pyrophoric (flammable in contact with air) nor self-heating,

- all tested representative magnesium powders with aD50 < 2,000 µmare flammable Cat. 1

- the flammability in contact with water of all tested representative magnesium powders depends on the particle-size distribution of the respective magnesium powder as follows:

o   All tested representative magnesium powders with a D50 ≥ 40 µm and < 200 µm are water-reactive Cat. 2

o   All tested representative magnesium powders with a D50 ≥ 200 µm < 2,000 µm are water-reactive Cat. 3

o   All tested representative magnesium powders with a D50 ≥ 2,000 µm but a D1 < 500 µm are water-reactive Cat 3

o   All tested representative magnesium powders with a D50 ≥ 2,000 µm and a D1 > 500 µm are non flammable in contact with water


Flammability additional key value for CSA: non flammable

Justification for classification or non-classification

The following classification & labelling of different magnesium powder grades in accordance with Regulation (EC) 1272/2008 is proposed:

Name

Index no.

EINECS no.

CAS no.

Classification

Labelling

Notes

 

Current entries of magnesium in Regulation (EC) 1272/2008

 

Magnesium powder (pyrophoric)

012-001-00-3

231-104-6

7439-95-4

Water-react. 1
Pyr. Sol. 1

Dgr
H260
H250

T

 

Magnesium, powder or turnings

012-002-00-9

231-104-6

Flam. Sol 1
Water-react. 2
Self-heat. 1

Dgr
H228
H261
H252

T

 

One additional entry is proposed based on new test results

 

Magnesium powder (non-pyrophoric, non-self heating):
- D50 > 50 µm - < 2,000 µm or

- D50 ≥ 2,000 µm but D1 < 500 µm

 

231-104-6

7439-95-4

Flam. Sol 1
Water-react. 2

Dgr
H228
H261

 

 

According to Note T of the existing entries “magnesium powder (pyrophoric) (Index no.: 012-001-00-3)” and “magnesium powder or turnings (Index no.: 012-002-00-9)” according to Regulation (EC) 1272/2008 Annex VI: “This substance may be marketed in a form which does not have the physical hazards as indicated by the classification in the entry in Part 3. If the results of the relevant method or methods in accordance with Part 2 of Annex I of Regulation (EC) 1272/2008 show that the specific form of substance marketed does not exhibit this physical property or these physical hazards, the substance shall be classified in accordance with the result or results of this test or these tests. Relevant information, including reference to the relevant test method(s) shall be included in the safety data sheet.”