An RSI Understanding Risk method
Application of TTC and margin-of-safety calculations
Application of TTC and margin-of-safety calculations is one of the methods used by Risk Sciences International to better understand risk.
Broadly
The Threshold of Toxicological Concern (TTC) and margin-of-safety (MoS) calculations offer structured approaches to risk estimation when chemical-specific toxicity data is limited or absent. TTC methods categorize chemicals into structural classes with known toxicity profiles and apply conservative thresholds to estimate safe exposure levels. MoS calculations compare observed or predicted exposures to a point of departure—such as a NOAEL—to determine if a sufficient safety buffer exists. These methods are highly useful in screening-level assessments and chemical prioritization. Their limitations include reliance on surrogate data, the assumption of default safety factors, and the potential for over- or under-protection.
More specifically
RSI applies TTC and MoS calculations within structured risk framing exercises, especially when evidence is partial but decisions must be made. The firm’s analysts integrate exposure modeling, chemical categorization, and uncertainty factors to produce interpretable results that can inform client decisions without overstating certainty. RSI can also embed TTC or MoS outputs into broader risk assessments, making it easier for clients to communicate defensible rationales to regulators or stakeholders. The combination of chemical expertise and policy experience makes RSI an effective interpreter and integrator of these methods.