sentences:  The airbomb effect, a loud bang and flash, continues to be a part of many larger fireworks.Since 1 April 2008, any firework which contains at least one tube containing over 5% flashpowder will be classed under United Nations regulations as 1.3G, with stricter transportation and storage regulation.This effectively means that any firework containing a flashpowder effect will not be legally available for sale after this date.