Safe-life criterion

In water, the concentration of toxaphene considered safe for protection of freshwater life is conservatively estimated to lie between 0.008 and 0.013 pg/L for marine life, it is 0.07 pg/L. This is in sharp contrast to the current recommended drinking water criterion for human health protection of 5.0 to 8.8 pg/L. Similarly, residues in fish tissue in excess of 0.4 to 0.6 mg/kg wet weight may be hazardous to fish health and should be considered as presumptive evidence of significant environmental contamination, although fish may contain up to 5.0 mg/kg before they are considered hazardous to human consumers. Toxaphene criteria for human health protection — which range in various foods from 0.1 mg/kg for sunflower seeds to 7.0 mg/kg in meat, fats, and citrus fruits — also appear adequate to safeguard sensitive species of wildlife. 

A more sophisticated procedure is described in ASTM D 1780 Standard practice for conducting creep tests of metal-to-metal adhesives. This standard covers the determination of the amount of creep of metal-to-metal adhesive bonds due to the combined effects of temperature, tensile shear stress, and time. The primary intention of this test procedure using single lap shear specimens is to provide basic data for the choice of safe working stresses for applications in which the allowable deformation within the service life of the structure is the criterion of failure. The standard is intended to be used with standard testing machines in combination with extensom-eters allowing to measure shear strain close to the bond line of the employed lap shear specimen. 

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