Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

Appearance/physical state/colour

Lithium hydroxide anhydrous and monohydrate are crystalline white, odourless solids.

Melting point

The determination of the melting point was performed according to OECD 102 by applying the differential scanning calorimetry. The melting point of lithium hydroxide anhydrous and lithium hydroxide monohydrate was determined to be 422.83 degree C and 423.93 degree C at 1013.25 hPa, respectively. According to the handbook data the melting point of lithium hydroxide anhydrous and monohydrate is between 445 and 471 degree C.

Boiling point

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 7.3 a boiling point study does not need to be conducted as the melting point of the test substance, lithium hydroxide monohydrate and anhydrous is above 300 degree C.

Density

According to the handbook-data the relative density of lithium hydroxide anhydrous and monohydrate is 1.5 g/cm3.

Particle size distribution (Granulometry)

The particle size distribution (volume distribution) of lithium hydroxide anhydrous and monohydrate was measured by laser diffraction in two studies. The values in the first study for lithium hydroxide anhydrous were as follows: d10: 4 um, d50: 14 um, d90: 32 um in absence of ambient air and in the other study: d10: 190 um, d50: 391 um, d90: 631 um in presence of ambient air. The values in the first study for lithium hydroxide monohydrate were as follows: d10: 202 um, d50: 440 um, d90: 570 um and in the other study: d10: 43 um, d50: 150 um, d90: 634 um. Differences may depend on the technique of production and / or measurement of particle size distribution incl. sample preparation. Consequently for lithium hydroxide anhydrous the percentage of particles < = 10 µm is in the range of 0.4 - 33 % and for Lithium hydroxide monohydrate in the range of 1 - 1.5 %.

Vapour pressure

In accordance with column 2 of Reach Regulation 1907/2006/EC Annex VII section 7.5, the vapour pressure does not need to be conducted if the melting point is above 300 degree C. Lithium hydroxide anhydrous and its monohydrate have a melting point of 471/473 degree C. Therefore, a study on vapour pressure is not applicable.

Partition coefficient

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 7.8, the test on partition coefficient n-octanol/water does not need to be conducted if the substance is inorganic. Lithium hydroxide and its monohydrate are inorganic compounds. The theoretical, calculated (EPIWIN) log Pow is -3.88, i.e. very low, as expected for an inorganic salt.

Water solubility

According to the handbook-data the water solubility of Lithium hydroxide anhydrous is 71 g/L - 125 g/L at 20 degree C and of Lithium hydroxide monohydrate 189 g/L - 223 g/L at 10 degree C.

Surface tension

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII, the determination of surface tension (required in section 7.6) only needs to be conducted if surface activity is expected or can be predicted. Based on the molecular structure, surface activity is not expected for Lithium hydroxide anhydrous and its monohydrate.

Flash point

As Lithium hydroxide anhydrous and its monohydrate are solids at room temperature, the determination of the flash point is scientifically unjustified and therefore was not performed. Instead, a test on flammability for solids upon contact in air was conducted (see IUCLID Section 4.13).

Auto flammability

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 7.12 a self-ignition temperature study does not need to be conducted as the substance is not flammable (see IUCLID section 4.13) and experience in handling gives no indication, that the substance is self-heating up to 400 degree C. As both criteria are applicable to Lithium hydroxide anhydrous and its monohydrate, no test was performed.

Flammability

Lithium hydroxide anhydrous and monohydrate are non-flammable according to the test of UN Recommendations on the Transport of Dangerous Goods, Manual of Test and Criteria, N1: Test Method for readily combustible solids, sub-section 33.2.1.4.

Flammability upon contact with water: The chemical structure of lithium hydroxide indicates that there are no groups associated with flammability properties (Ref.: R.7a: Guidance on information requirements and chemical safety assessment, EU-Document (May 2008)). Further, experience in handling and use does not indicate flammability upon contact with water.

The chemical structure of lithium hydroxide indicates that there are no groups associated with pyrophoric properties. The test substance does not contain any chemical group that might lead to spontaneous ignition shortly after coming into contact with air at room temperature (Ref.: R.7a: Guidance on information requirements and chemical safety assessment, EU-Document (May 2008)). Based on experience in handling and use there is also no indicator for pyrophoric properties.

Explosiveness

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 7.11, the determination of explosiveness does not need to be conducted as there are no chemical groups associated with explosive properties present in lithium hydroxide anhydrous and its monohydrate (refer to Guidance on information requirements and chemical safety assessment, Chapter R.7a).

Oxidising properties

A test on oxidising properties (required in section 7.13 of REACH Regulation 1907/2006/EC Annex VII) does not need to be conducted as there are no chemical groups associated with oxidising properties present in lithium hydroxide anhydrous and its monohydrate (refer to Guidance on information requirements and chemical safety assessment, Chapter R.7a).

Stability in organic solvents and identity of relevant degradation products

In accordance with column 2 REACH Regulation 1907/2006/EC Annex IX section 7.15, the study which examines stability in organic solvents does not need to be conducted as the test substance lithium hydroxide anhydrous and the respective monohydrate are inorganic substances.

Dissociation constant

Lithium hydroxide is usually considered to be a strong base, almost completely dissociated in aqueous solution. Based on the available data the pKa of lithium hydroxide anhydrous is between 13.8 and 14.18 at 20°C. This result demonstrates the extreme alkaline character of lithium hydroxide anhydrous in aqueous solutions. For lithium hydroxide monohydrate also full dissociation is very likely, whereas the pH value of a solution of comparable morality is expected to be lower, due to the content of crystal water (less hydroxyl ions).

Viscosity

The study which examines viscosity and is required according to REACH Regulation 1907/2006/EC Annex IX section 7.17 does not need to be conducted as the test substance lithium hydroxide and the respective monohydrate are no liquids.