Lead is also used in ceramic glazes and as a stabilizer in plastics. Lead was used extensively as a corrosion inhibitor and pigment in paints but concerns over its toxicity led to the CPSC in 1977 to ban the use of lead in paint for residential and public buildings.
The first digit assigned to all Visa cards is four, and the second through sixth numbers are connected to the financial institution. Then, either the seventh through 12th numbers, or the seventh through 15th, are the account number, while that final 13th or 16th digit is the check number.
The first six digits of the credit card number (including the initial MII digit) make up the issuer identifier, which denotes the credit card network to which the number belongs. Some of the better-known issuer identifiers include: 1  American Express -- 34xxxx and 37xxxx. 2  Visa -- 4xxxxx. 3  MasterCard -- 51xxxx-55xxxx.