Table 2.

Limitations of in vitro test data for ENMs. Adapted from (Lai, 2017).

• No single short-term test can be used to predict all health effects of ENMs

• A large number of false positive and false negative results occur

• Effects at high dose levels may not extrapolate to low-dose levels

• Endpoints identified in short-term tests may not be predictive of long-term exposure effects

• Different cell lines may yield different responses

• Some in vitro tests involve release of protein, but various types of ENMs can absorb protein, thus confounding results (Dutta et ah, 2007)

• Various physico-chemical characteristics of ENMs can interfere with some in vitro tests (e.g. fluorescent quantum dots in a fluorescent assay) (Monteiro-Riviere and Inman, 2006)

• Particle kinetics of ENMs in culture media often not considered, resulting in erroneous interpretations of dose-response relationship (Mecke et ah, 2005)