"The test material, HFA-134a (1,1,1,2-tetrafluoroethane; CAS Register No. 811-97-2), was specially prepared to contain relatively high levels of each related fluorocarbon and feedstock impurities that may be formed or carried over into the final product during synthesis."

"To ensure adequate assessment of the toxicity of HFA-134a and its related impurities, a ’toxicology grade’ HFA-134a was specifically prepared containing essentially all likely impurities at concentrations of between 2 and 1000 p.p.m. depending upon their toxicity and likely maximum concentration present in production HFA-134a. Concentrations of impurities in each batch of HFA-134a were measured using specific gas chromatographic methods. ’Toxicology grade’ HFA-134a was approximately 99.3% pure. ’Toxicology grade’ HFA-134a, supplied as a liquefied compressed gas, was filtered into pressurised metered-dose inhaler packs designed to give a nominal 200 actuations, each of 75 mg HFA134a." 

"The test material, HFA-134a (1,1,1,2-tetrafluoroethane; CAS Register No. 811-97-2), was specially prepared to contain relatively high levels of each related fluorocarbon and feedstock impurities that may be formed or carried over into the final product during synthesis."

"To ensure adequate assessment of the toxicity of HFA-134a and its related impurities, a ’toxicology grade’ HFA-134a was specifically prepared containing essentially all likely impurities at concentrations of between 2 and 1000 p.p.m. depending upon their toxicity and likely maximum concentration present in production HFA-134a. Concentrations of impurities in each batch of HFA-134a were measured using specific gas chromatographic methods. ’Toxicology grade’ HFA-134a was approximately 99.3% pure. ’Toxicology grade’ HFA-134a, supplied as a liquefied compressed gas, was filtered into pressurised metered-dose inhaler packs designed to give a nominal 200 actuations, each of 75 mg HFA134a."