and TR50 values for each test material compared to 20% SDS, for each of the 7 studies, are shown in Figs. 1B– 7B. The range of TR50 values for 20% SDS across all 7 studies (summarized in Table 2) was within historical ranges (Robinson et al., 1998). Individual values showed some evidence of seasonal variation (see Section 4). The TR50 values for all of the SDA formulations are compiled in Table 3 along with the notation of irritating or non-irritating based on the comparisons to the 20% SDS benchmark. Comparison of these TR50 values
within and between product formulation categories enabled a rough determination of relative irritation potentials (see Section 4).
4. Discussion
Assessment of the skin irritation potential of product ingredients and final formulations is a critical step in the pre-market safety evaluation process (Robinson et al.,