What characteristic might indicate the presence of dry ice or dangerous goods?

The presence of dry ice or dangerous goods is often indicated by specific markings and ventilation features. When goods are packaged with clear indications or warnings that denote the contents are hazardous, it serves both as a safety measure and as a guideline for handling and transport. Proper markings can include classifications, handling instructions, and other relevant safety information, while ventilation is essential for dangerous goods that may emit gases or vapors—ensuring that these are safely dispersed and do not accumulate to dangerous levels.

Heavy weight, tight seals, or clear packaging alone do not sufficiently indicate the presence of hazardous substances, as these characteristics can apply to a wide range of non-hazardous items as well. Therefore, marked and ventilated packaging is a critical safety aspect that specifically points to the presence of dry ice or dangerous goods.