To report hazardous materials in Hillingdon, you should ensure that any dangerous chemicals are stored properly and labelled correctly. If you encounter a chemical spillage or hazardous material in your area, follow local news updates and consider reporting it to the council directly.
You can find more guidance and report hazardous materials through the following link: report hazardous materials.
If you believe you have found a specific hazard, acting promptly is important for ensuring safety.