In preparation for the festival in August, Green Man organizers are reviewing their "not to bring list.".
This comes after the later-in-June Glastonbury Festival requested that attendees refrain from bringing disposable vapes this year.
Some of the items already on Green Man's list include fireworks, explosives, pets, and glass bottles.
The festival's organizers promised to make a decision regarding the addition of disposable vapes in August.
Disposable vapes were added to Glastonbury's "what not to bring" list earlier this week.
Disposable vapes "pollute the environment and can be hazardous at waste centers," according to the organization's updated website message.
Disposable vapes are currently excluded from the list of "forbidden items," according to the Green Man website.
However, the list does advise festival-goers to bring "a sense of humor, a smile, exquisite music taste, and a friendly attitude" along.
This year's Green Man festival, which takes place from August 17 to 20, features performances by First Aid Kit, Devo, and Spiritualized as its headliners.
It will take place in the Black Mountains close to Crickhowell, Powys.