A bus is offered allowed hazardous materials totaling 400 pounds, with 75 pounds in the largest single class. What is the key remaining issue?

1. The shipment is within the listed weight limits, but it still must be allowed, marked, and secured correctly
2. It is automatically illegal because any hazardous material over 50 pounds is forbidden
3. It is automatically legal and needs no markings or securement
4. It is illegal because the per-class limit is 25 pounds