The Blast Box (爆薬箱 (ばくやくばこ), bakuyaku bako: literally, explosive box)-also called a DANGER box is a heavy item which has the appearance of a crate with a fire hazard label on its sides. When destroyed, the box will explode with typical fire properties and great vertical knockback, often KOing anyone too close. However, if Stone was used, there would be no damage, but knockback still applies meaning the player with Kirby can still be KO'd at high percent. It usually takes multiple hits to destroy it (about 30% total), but it detonates instantly when attacked with a fire-based attack. This item can also be picked up and thrown a very short distance (usually just in front of the character that threw it). Although it is a heavy item, it can appear out of carriers such as Barrels and Capsules.
A Blast Box does have a slight amount of tactical strength when playing a match with items. It can be remotely detonated by using ranged attacks (especially fire-based ones) and thus, with a well placed projectile and good timing, it can be detonated while an opponent is near.
An explosive-filled box that will detonate when the box is broken. The box can be smashed with normal attacks and will also catch fire and blow up if it's exposed to any flame. Unlike ordinary crates, blast boxes do not change their appearance from stage to stage. There's one fundamental rule when dealing with these items: be out of range when they blow.
In Super Smash Bros. for Nintendo 3DS and Wii U
A highly flammable box packed full of gunpowder. The player who last threw the box will get credit for any KOs it causes. Setting off the box will result in a massive explosion, and you've only yourself to blame if you blow yourself up. It says DANGER right on the front.