五颜六色，很漂亮！但居然这么危险！

Core Viewpoint - The use of hydrogen balloons poses significant safety risks due to their flammable nature, leading to incidents of explosions and fires, especially during festive occasions [1][5]. Group 1: Safety Risks - Hydrogen balloons can explode when ignited, causing severe injuries, as evidenced by incidents where children have been burned [1]. - The risk of explosion is heightened when hydrogen balloons come into contact with static electricity, open flames, or are exposed to high temperatures [5]. - Even in the absence of flames, hydrogen balloons can still explode due to chemical interactions with organic compounds found in certain fruits, which can weaken the balloon's material [5]. Group 2: Market Dynamics - Despite the dangers, hydrogen balloons are still sold because they are significantly cheaper than helium balloons, which are about ten times more expensive [6]. - Some vendors knowingly sell hydrogen balloons, prioritizing profit over safety, which raises concerns about public safety [6]. Group 3: Public Safety Recommendations - Authorities emphasize the importance of adhering to safety regulations regarding the sale and use of hydrogen balloons and similar items during crowded events [6].