Final answer:
The most common route of entry of hazardous chemicals into the body during spray painting and blasting degreasing operations is inhalation.
Step-by-step explanation:
The most common route of entry of hazardous chemicals into the body during spray painting, blasting degreasing, and other operations is inhalation. Inhalation occurs when chemicals are breathed in and enter the lungs. This route of exposure is commonly seen in settings where spraying operations take place in enclosed environments with poor ventilation systems.