Magnesium

Endpoint summary

Additional information

Data for the physico-chemical properties of magnesium were provided based on studies for the following endpoints: (i) laser diffraction and dustiness testing (ii) water solubility testing according to OECD 105 (incl. modifications) and transformation dissolution testing according to OECD series 29 (iii) self heating (screening tests initiated with three samples of different particle size distribution) (iv) pyrophoric properties (tests initiated with three samples of different particle size distribution) (v) flammability in contact with water (tests initiated with seven samples of different particle size distribution) and (vi) flammability testing (tests initiated with two samples of different particle size distribution). The other endpoints are based on handbook data and/or long time experiences in handling.

It is noted here that handbook data for physico-chemical properties are considered to be from a trusted source acc. to "ECHA, Guidance on information requirements and chemical safety assessment – Chapter R.7a: Endpoint specific guidance" and therefore, theses data could be regarded as valid.

The results of the studies are reported in the endpoint summary as well as in the accompanying IUCLID database. Data for several endpoints were waived due to intrinsic properties of magnesium or based on the criteria as laid down in Regulation (EC) 1907/2008 (CLP) as described above.

Nevertheless, studies on flammability, pyrophoric properties, self-heating properties and flammability in contact with water were initiated at the German Federal Institute of Materials research and Testing “BAM - Bundesanstalt für Materialforschung und -prüfung” in accordance to the current valid transport regulation “UN recommendations on transport of dangerous good, manual of tests and criteria, part III”. The submitter explicitly note that the legal classification (CLP Annex VI) does not reflect the long-time experience of the magnesium industry and has doubts that magnesium powder is self-heating or/and is flammable in contact with air. During literature search no science based data could be found which support the legal classification of magnesium being self-heating or being flammable in contact with water/air.

The results of new physico-chemical testing indicate that the differentiation between the two powders “magnesium powder (pyrophoric), EC # 231-104-6, CAS # 7439-95-4” and “magnesium powder or turnings, EC # 231-104-6, CAS # -” is arbitrary 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:

 (i) all tested representative magnesium powders with a D50 ≥ 40 µm and < 200 µm are water-reactive Cat. 2

(ii) all tested representative magnesium powders with a D50 ≥ 200 µm < 2,000 µm are water-reactive Cat. 3

(iii) all tested representative magnesium powders with a D50 ≥ 2,000 µm but a D1 < 500 µm are water-reactive Cat 3

(iv) all tested representative magnesium powders with a D50 ≥ 2,000 µm and a D1 > 500 µm are non flammable in contact with water

Hence, a new C&L is supposed for magnesium powder as follows:

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