Titanium nitride

Nanomaterial dustiness

Administrative data

Endpoint:

nanomaterial dustiness

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING


Assessment for nanomaterial dustiness can be waivered because the substance is always used in a liquid form and as the use profile does not lead to dust, vapour or aerosol formation dustiness measurement is not relevant. This justification applies for the following reasons:

1) TiN (nanoform) is never supplied or used as a solid due to its high flammability which results in the nanoparticle powder form presenting a significant fire risk. Hence, for fire safety reasons, the material is always supplied and used in a liquid mixture of 15.91% TiN (nanoform) in 84.09% Mono Ethylene Glycol (MEG) (CAS:107-21-1). The preparation of the mixture takes place at an industrial plant which is located outside the EU and the TiN (nanoform) / MEG mixture is imported into the EU in 200L steel drums as a ready to use formulation. As a dispersion in a low volatility liquid the product does not easily dry out to form residues and such residues have not been encountered during use experience.

2) Assessment of the use conditions further confirm that exposure to dusts or vapours is not a relevant route of exposure as outlined in a and b below:

a) The TiN (nanoform) / MEG formulation as imported into the EU in 200L drums is used directly in an industrial process. The formulation is pumped out of the opened drum using a lance into a closed vessel to produce a masterbatch formulation for use in product manufacture. The product may also be bead milled, where it is circulated from a closed vessel into a milling chamber. Once the TiN (nanoform) is in the manufacturing vessels it is in a closed system and there is no potential for exposure to dusts or vapours containing TiN (nanoform) during the manufacture process.

b) The drum emptying process is a semi-open process; however, it has been assessed as presenting a low risk of airborne exposure due to its controlled nature and the low volatility of the liquid. Standard chemical industry PPE of overalls, gloves and eye protection are worn during this work (and worn as standard on the plant given its chemical manufacturing setting). Respiratory protection is not worn because vapours and/or dusts are not generated.


3) The TiN (nanoform) is intended to be completely consumed in the manufacturing process although residues may remain in the product (with no technical function) these will be bound into the material, at very low concentrations and subject to limits set by food contact regulations. It is therefore considered that downstream exposure is of no concern and final product use does not present any measurable risk for direct or secondary human or environmental exposure.

4) There are no TiN (nanoform) releases to solid waste, air or drainage systems. The empty TiN (nanoform) drums are rinsed with 5kg MEG to remove residues from the sides of the drums and the rinse fluid is added to the masterbatch. Additionally, due to the stickiness/viscosity of the material some scraping of the sides of the drum may be required to remove all material from the drum. A small amount of liquid residue may be present on the drum interiors following rinsing; however, this is not considered to be of concern as it will mainly be MEG. The steel drums in which the TiN (nanoform) /MEG mixture is supplied are disposed of to a specialist commercial waste disposal operator.