1,1,1,2-Tetrachloro-2,2-bis-(4-fluoro-phenyl)-ethane, also known as DDT, is a synthetic chemical compound with the molecular formula C14H8Cl4F2. It was widely used as an insecticide to control pests and diseases in agriculture and public health. DDT is characterized by its stability, low cost, and effectiveness against a broad range of insects. However, due to its persistence in the environment, bioaccumulation in the food chain, and potential harmful effects on wildlife and human health, its use has been banned or restricted in many countries. Despite its historical significance, DDT remains a controversial chemical due to its negative environmental and health impacts.
The CAS Registry Mumber 1693-26-1 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 1,6,9 and 3 respectively; the second part has 2 digits, 2 and 6 respectively. Calculate Digit Verification of CAS Registry Number 1693-26: (6*1)+(5*6)+(4*9)+(3*3)+(2*2)+(1*6)=91 91 % 10 = 1 So 1693-26-1 is a valid CAS Registry Number.