Considerations and Challenges for Acute Inhalation Toxicity Testing and Classification of Zinc Sulphide Under REACH.

Zinc sulphide is a widely used inorganic powder, and its production has reached quantities greater than 1000 t/year. Therefore, in accordance with OECD guideline 436, an acute inhalation test was implemented to provide more accurate data. This study is crucial for ensuring the safety of workers exposed to zinc sulphide dust and complying with regulatory requirements for REACH.

Updated assessment of the genotoxic potential of titanium dioxide based on reviews of in vitro comet, mode of action and cellular uptake studies, and recent publications.

In 2021 the European Food Safety Authority (EFSA) concluded that "A concern for genotoxicity of TiO2 particles that may be present in E 171 could therefore not be ruled out.". A detailed review of the genotoxicity of titanium dioxide (TiO) was subsequently published by Kirkland et al.

A weight of evidence review of the genotoxicity of titanium dioxide (TiO).

Titanium dioxide is a ubiquitous white material found in a diverse range of products from foods to sunscreens, as a pigment and thickener, amongst other uses. Titanium dioxide has been considered no longer safe for use in foods (nano and microparticles of E171) by the European Food Safety Authority (EFSA) due to concerns over genotoxicity. There are however, conflicting opinions regarding the safety of Titanium dioxide.

The underlying mode of action for lung tumors in a tiered approach to the assessment of inhaled cobalt compounds.

A mode of action (MOA) for cobalt substances based on the "International Programme on Chemical Safety Conceptual Framework for Evaluating a MOA for Chemical Carcinogenesis" is presented. The data recorded therein were generated in a tiered testing program described in the preceding papers of this special issue, as well as data from the public domain. The following parameters were included in the evaluation: solubility of cobalt substances in artificial lung fluids (bioelution), in vitro biomarkers for cytotoxicity, reactive oxygen species and hypoxia mimicry, inhalation toxicity following acute exposure and repeated dose inhalation effects.

A tiered approach to investigate the inhalation toxicity of cobalt substances. Tier 4: Effects from a 28-day inhalation toxicity study with tricobalt tetraoxide in rats.

Lung cancer following inhalation in rodents is a major concern regarding exposure to cobalt substances. However, little information is available on adverse effects and toxicity following long-term inhalation exposure to poorly soluble cobalt substances with low bioavailability. Thus, the present study focused on pulmonary effects of the poorly soluble tricobalt tetraoxide (5, 20, 80 mg/m³) in a 28-day inhalation exposure study.