Acute toxicity of high concentrations of carbon dioxide in rats.

Subterranean storage of carbon dioxide (CO2) has been proposed to diminish atmospheric increases of this greenhouse gas. To contribute to risk assessment of accidental release associated with handling, transport and storage, rats were exposed to high concentrations (targets 40, 43 and 50 volume %) of CO2. The oxygen concentrations dropped as a result, but were not supplemented.

Inhaled multiwalled carbon nanotubes modulate the immune response of trimellitic anhydride-induced chemical respiratory allergy in brown Norway rats.

The interaction between exposure to nanomaterials and existing inflammatory conditions has not been fully established. Multiwalled carbon nanotubes (MWCNT; Nanocyl NC 7000 CAS no. 7782-42-5; count median diameter in atmosphere 61 ± 5 nm) were tested by inhalation in high Immunoglobulin E (IgE)-responding Brown Norway (BN) rats with trimellitic anhydride (TMA)-induced respiratory allergy.

The acute, genetic, developmental and inhalation toxicology of trans-1-chloro,3,3,3-trifluoropropene (HCFO-1233zd(E)).

Trans-1-chloro,3,3,3-trifluoropropene (HCFO-1233zd(E)) is being developed as a foam blowing agent, refrigerant and solvent because it has a very low global warming potential (<10), as contrasted to the hydrofluorocarbons (>500). The toxicology profile is described. The acute 4-hour 50% lethal concentration value in rats receiving HCFO-1233zd(E) was 120 000 ppm.

Comparative hazard identification of nano- and micro-sized cerium oxide particles based on 28-day inhalation studies in rats.

There are many uncertainties regarding the hazard of nanosized particles compared to the bulk material of the parent chemical. Here, the authors assess the comparative hazard of two nanoscale (NM-211 and NM-212) and one microscale (NM-213) cerium oxide materials in 28-day inhalation toxicity studies in rats (according to Organisation for Economic Co-operation and Development technical guidelines). All three materials gave rise to a dose-dependent pulmonary inflammation and lung cell damage but without gross pathological changes immediately after exposure.

The acute, developmental, genetic and inhalation toxicology of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

2,3,3,3-Tetrafluoropropene (HFO-1234yf) is being developed as a refrigerant because it has a very low global warming potential (less than 10), as contrasted to the hydrofluorocarbons, which is intended to replace with values of over 500. Several toxicology studies were conducted to develop a toxicology profile for this material. There was no lethality in mice and rats receiving single 4-hour exposures up to 101,850 or 405,800 ppm, respectively.