In 2007 the National Academies of Sciences released “Toxicity Testing in the 21st Century: A Vision and a Strategy”, a new toxicological paradigm, moving away from the idea of high dose animal tests as the ‘gold standard’ and focusing on the use of human cell lines.

The European Tobacco Product Directive (2014/40/EU), requires data for priority additives regarding Carcinogenic, Mutagenic or Reproductive (CMR) properties either in the neat form, or increasing the CMR properties of the combusted product to a significant or measurable degree.

Traditional reproductive toxicity testing utilises a significant proportion of the animals used for toxicity testing, with a limited ability to predict reproductive toxicity in humans. Previous reproductive studies with rats exposed to either 1R4F or 2R4F cigarette smoke, exhibited no adverse effects on various reproductive endpoints in a multi-generational study. The only treatment related effects were decreased body weight gain in both dams and pups, associated with delayed ossification of occipital bones and sternebrae.

A human developmental toxicology screening assay is considered more appropriate to look for the possible effects of additives on humans than animal related assays, due to known species differences.

Stemina have developed a metabolomics based assay using human Induced Pluripotent Stem Cells (IPSCs) looking at the disruption in the ratio of two key amino acids (ornithine and cysteine), as a biomarker of development toxicity. The assay has a high concordance with both human developmental toxicants and non-developmental toxicants (82% overall, 0.71 sensitivity and specificity 1.0). This assay has been used by the United States Environmental Protection Agency (EPA) as part of ToxCast library for >1000 chemicals in support of Tox21. This is the first time a cigarette smoke condensate has been used in the assay, however, it appears to be able to measure the relative developmental toxicity potential of tobacco condensates.