Lighters?
A lighter is a portable device used to create a flame. It consists of a metal or plastic container filled with lighter fluid (usually naphtha or liquid butane under pressure), as well as a means of ignition and some provision for extinguishing the flame, by depriving it of either air or fuel.

Operation
Lighters using naphtha have a wick which is immersed in the fluid and becomes saturated. This type usually has a fiber packing material which absorbs the liquid to keep it from leaking. They also must have an enclosed top to prevent the volatile liquid from evaporating, and to conveniently extinguish the flame. Butane lighters have a valved orifice that meters the butane as it escapes as a gas.

A spark is created by striking metal against a flint, or by pressing a button that compresses a piezoelectric crystal, generating a voltaic arc (see Piezo ignition). In naphtha lighters the liquid is volatile enough that flammable gas is present as soon as the top of the lighter is opened. Butane lighters combine the striking action with the opening of the valve to release gas. The spark ignites the flammable gas causing a flame to come out of the lighter which continues until either the top is closed (naphtha type), or the valve is released (butane type).

A metal enclosure with air holes generally surrounds the flame, and is designed to allow mixing of fuel and air while making the lighter less sensitive to wind. The high energy jet in butane lighters allows mixing to be accomplished by using Bernoulli's principle, so that the air hole(s) in this type tend to be much smaller and farther from the flame. In a plastic butane lighter this metal enclosure also regulates the distance from the valve to the beginning of the flame. If the flame is too close to the valve, there is a risk of the flame melting some, most, or all of the plastic components of the lighter which are in close proximity to the valve.

History
The first lighter, Döbereiner's lamp, was invented by Johann Wolfgang Döbereiner in 1823. It stayed in production until 1880. The development of lighters accelerated during the first World War. Soldiers used matches to find their way in the dark, but the intense initial flare of matches gave away their position, and many lives were lost because of this. So the need for fire without a large initial flare was born. Inventors started improving the design of lighters and by 1918 when the war ended, they were able to be produced fast, easier and cheaper.

Safety
Two technical standards relate to the safety of lighters. The International Standard EN ISO 9994:2002 establishes non-functional specifications on quality, reliability and safety of lighters and appropriate test procedures. For instance, a lighter should generate flame only through positive action on the part of the user, two or more independent actions by the user, or an actuating force greater than or equal to 15 N. The standard also specifies other safety features, such as as the lighter's maximum flame height and its resistance to elevated temperatures, dropping, and damages from continuous burning. However, the standard does not include child resistance specifications. In addition, the European standard EN 13869:2002 establishes child-resistance specifications and defines as novelty lighters those that resemble another object commonly recognized as appealing to children younger than 51 months, or those that have entertaining audio or animated effects. As matches, lighters, and other heat sources are the leading causes of fire deaths for children many jurisdictions, such as the EU,[5] have forbidden the marketing of novelty or non-child resistant lighters. Examples of child resistance features, include the use of a smooth or shielded spark wheel.