Publications of the BASF Safety Research on Nanomaterials

Study: Dermal penetration studies in human and porcine skin in vitro.

Result: TiO₂ and ZnO particles from BASF do not pass through healthy skin.

Study: Inhalation studies in rats.

Result: In studies performed to date, particles have mainly been found in extracellular spaces and in macrophages in the lung. The substances investigated were TiO₂, ZnO, ZrO, CeO, amorphous silicates, carbon black and Multiwall Carbonnanotubes. Further studies are ongoing.

Study: Inhalation studies in rats.

Result: Below certain particle concentrations no effect is observed. At higher concentrations, mainly an inflammation of the lung is observed which subsides a certain time after exposure.

Study: Short-term inhalation studies and 90 day inhalation studies in rats

Result: Two types of multiwall carbon nanotubes (MWCNT) were tested in short-term inhalation studies. Both caused significant pulmonary effects even at the lowest concentrations tested. One MWCNT was tested in a 90 day inhalation study: Pulmonary granulomas were found in the lung even at the lowest concentration (0,1 mg/m3); under certain circumstances, granulomas may develop into tumors.

Study: Intravenous study in rats.

Result: Particles injected into the vein are found mainly in the liver and spleen, but without toxicologically relevant effects on these and other organs. 5 mg TiO₂ per kg body weight was studied.

Study: Ames test.

Result: Various preparations of the particles (standard, with protein, with lung surfactant) caused no genetic changes in the Ames test. They also caused no such changes in bacteria used to demonstrate oxidative DNA damage. Substances studied were TiO₂, ZnO, carbon black, multiwall carbon nanotubes, iron oxide and amorphous silicates. Further studies are planned.

Study: Aquatic toxicity studies on Daphnia.

Result: The acute aquatic toxicity was low; the chronic toxicity did not differ essentially from that of non-nanoscale materials. TiO₂ and ZnO were studied.

We want to examine this aspect together with other partners in a project for which an application has been submitted to the EU.

We have contributed through various activities to developing test methods for nanomaterials:

1. Generation and characterization of atmospheres for inhalation studies

Result: Particles of nanoscale materials form dust consisting mainly of agglomerates and only a smaller proportion of nanoparticles.

2. Short-term inhalation test for nanoscale materials

Result: A short-term inhalation test for testing of nanoparticles has been developed. By means of this test the effects of nanoparticles in the lungs can be assessed faster, more cost-efficient and with a significantly reduced number of animals. The respective operating procedure serves as a standard for all partners of the NanoCare project. Moreover, the test is being introduced to OECD Working Parties on Nanomaterials.

3. Preparation and characterization of nanoparticle-suspension for toxicological tests (in vitro)

Result: Compilation of instructions and provision of guidance for the manufacture and characterization of nanoparticle suspensions. This compilation, too, serves as a standard for all further partners of the NanoCare project initiated by the German Federal Ministry of Education and Research and is supposed to be introduced to the OECD nano working groups.

4. In vitro methods for estimating effects on the lung

Result: We are currently working on pulmonary sections as a possible in vitro model for estimating potential effects.