Thickening test work

Apart from gastropods, harmful effects of TBT have also been demonstrated in oysters (Environmental Health Criteria 116, Thain and Waldock 1986). Early work established that adult Pacific oysters (Crassostrea gigas) showed shell thickening caused by the development of gel centers when exposed to 0.2 pg/L of TBT fluoride (Alzieu et al. 1982). Subsequent work established the no observable effect level (NOEL) for shell thickening in this, the most sensitive of the tested species, at about 20 ng/L. It has been suggested that shell thickening is a consequence of the effect of TBT on mitochondrial oxidative phosphorylation (Alzieu et al. 1982). Reduced ATP production may retard the function of Ca++ ATPase, which is responsible for the Ca++ transport that leads to CaCOj deposition during the course of shell formation. Abnormal calcification causes distortion of the shell layers. 

With the advent of two-in-one shampoos, a new era has begun in cosmetic science. Differences in the performance between different conditioning shampoos can be relatively large, and these can be detected in laboratory tests, in half-head tests, and even in consumer tests on cell sizes smaller than N = 100. To the cosmetic scientist, this is a pleasant situation. We can now turn our attention to real product performance. We can truly work to create products that are really better, not only in the laboratory but also in the marketplace. This situation was created by a combination of new technology and consumers becoming willing to accept different standards of performance for shampoos, and I believe this same situation exists for other opportunities in hair care in the future (e.g., hair body or hair thickening shampoos). 

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