The report focuses on the potential for products to trigger wider cigarette use in children.
The health experts stated that the products might pose a threat to adolescents and the foetuses of pregnant women.
As a result of this, the WHO has called for a ban on advertisements that could encourage children and non-smokers to use the devices.
The report states that fruit, candy or alcoholic-drink style flavours should be prohibited until it can be proved that they are not attractive to minors.
The health body says that while the devices are likely to be less harmful than traditional cigarettes, there is currently insufficient evidence pointing towards e-cigarettes helping users quit smoking.
The WHO says no more claims must be made saying the devices can help smokers quit, until there is firm evidence to support this.
The report will be discussed in further detail in a meeting in October.
