Final answer:
The hazard class for 'Rags, oily' is typically class 4.2, denoting spontaneously combustible materials. This classification is guided by CFR criteria on ignitable hazardous materials and requires proper hazardous waste management practices.
Step-by-step explanation:
The hazard class or division for "Rags, oily" depends on their specific characteristics but they typically fall into hazard class 4.2, which pertains to spontaneously combustible materials under the United States Department of Transportation regulations. These rags can ignite spontaneously if not properly managed due to the oils they contain, which can have low flash points or be reactive under certain conditions. The classification is based on the criteria outlined in Title 40 of the Code of Federal Regulations (CFR), which includes materials that are ignitable or present a significant risk of combustion. Therefore, proper handling of oily rags includes storage and disposal in accordance with established hazardous waste management protocols to avoid environmental contamination or health hazards.