Sub-chronic studies on rodents (rats and mice) are needed to determine the level of safety and toxicity possessed by the test substance (study compound) via repeated administration over a relatively short period. They serve towards broader evaluations, including identification of potential target organs, toxic dose, optimal dosages to use, and evaluation of other parameters such as how appetising a new foodstuff may be.

Choosing the most suitable administration pathway is of the utmost importance: it should as far as possible reproduce the human exposure scenario and the test substance metabolism in the human organism, thus optimising results and increasing their scientific worth and reliability.

OECD Guideline 407: Repeated Dose 28-Day Oral Toxicity Study in Rodents
OECD Guideline 408: Repeated Dose 90-Day Oral Toxicity Study in Rodents
OECD Guideline 410: Repeated Dose Dermal Toxicity: 21/28-day Study
OECD Guideline 411: Subchronic Dermal Toxicity: 90-day Study