Besides the NFPA diamond, other labeling systems may also be used for secondary containers of hazardous chemicals. These labels also use a color-coded system to alert the user to the type of hazard posed by the chemical substance. A numeric system is used that rates the degree of hazard. The colors that are used indicate the same types of hazards as the NFPA diamond and the numbering system is usually the same with "0" indicating no hazard and "4" indicating the greatest hazard, although the criteria for assigning a number may vary. A section may be included on the label to identify personnel protective equipment (PPE) that should be used when handling that chemical. The recommended PPE is appropriate to the hazard's route of entry to the body and protects the potentially affected organs.
An example of one type of labeling system is shown on the right.
Image used with permission ©Lab Safety Supply, Janesville, WI