While iconography is ubiquitous, it’s not always “universal”. Meaning can vary wildly from culture to culture, or even from industry to industry, so you’ll have to think through how to choose the right visual metaphor.
When you decide to use an icon, you need to consider who interacts with it and where.
Are you communicating to a kindergartner or a nuclear physicist? Are they sitting in a greasy spoon diner perusing a menu, or at the airport frantically looking for a bathroom? Are they checking their email inbox, or is their vintage Macintosh about to explode? (No need to duck for fear of computer shrapnel just yet, friend. All will be made clear soon enough…)