After an emergency road incident is brought under control, what is the mandatory regulatory requirement for handling contaminated soil, used absorbents, and chemical cleanup residue under the Law on the Prevention and Control of Environmental Pollution by Solid Waste?

1. All chemical residue, contaminated soil, and used absorbents must be classified as Hazardous Waste (危险废物) and transferred to a certified entity with hazardous waste disposal qualifications
2. Dump all contaminated soil into the nearest public park flowerbed at night
3. Bury the toxic sludge inside a school playground sandbox
4. Sell the chemical-soaked rags to local restaurants as cooking fuel