Caffeine was long known to provide that extra boost of energy in the form of a cup of tea or coffee. However, the love affair of the Americans with caffeine seems to have turned into an addiction, a reason enough to make the state federal bodies worry.

Recently, the U.S. Food and Drug Administration, or FDA, has issued warning letters to five manufacturers of pure powdered caffeine in an attempt to curb or minimize the ingestion of caffeine in its pure form.

According to FDA, the instructions of information provided on the labels of the powdered caffeine manufactured by these companies are misleading and potentially dangerous. The FDA decided to issue the warning letter, following the death of two teenagers in 2014 after consuming caffeine supplements.

"While consumers of caffeinated products such as coffee, tea, and soda may be aware of caffeine's less serious effects -- such as nervousness and tremors -- they may not be aware that these pure powdered caffeine products are much more potent and can cause serious health effects,” stated FDA in a press release.

The FDA further revealed the shocking fact that one teaspoon of powdered pure caffeine is nearly equivalent to the caffeine contained in 28 cups of regular coffee. While excessive consumption of normal caffeine can lead to shakiness, escalated heartbeat and nausea, a slight increased consumption of pure caffeine can lead to erratic heartbeat, seizures and might prove fatal.

As a next step, the FDA has decided to keep an eye on all the pure powdered caffeine-based products available in the market. If the product violated the guidelines or ignores the warning issued by the agency, then the FDA will take an enforcement action, which may lead to seizure of the product of complete stoppage of its manufacturing.