Failure to use class 4.2 labels appropriately on shipments can result in severe penalties, including fines and legal action. Non-compliance not only poses serious safety risks but also contravenes transport and hazardous material regulations. For detailed information about the fines and penalties for non-compliance with the use of spontaneous combustion labels in the UK, you should consult the Health and Safety Executive (HSE) which provides extensive resources on the regulations for transporting dangerous goods. Additionally, the official UK Government website offers comprehensive access to relevant legislation. Trade associations such as the Chemical Business Association or the Freight Transport Association also offer guidance and updates on regulatory compliance.