Research

Sodium Citrate

The first ingredient that I examined was Sodium Citrate.

As can be seen in the picture above, Sodium Citrate consists of three carboxyl groups and one hydroxyl group.

The bonds are mostly non polar covalent except for the NaO bonds, which are polar, and the OH which is a hydrogen bond.

Sodium Citrate functions in the product as a pH buffer, specifically preventing the pH from becoming acidic. A buffer's purpose is to stabilize the pH and prevent major changes, which is very important for a product that's being put in a sensitive organ like the eyes. It can neutralize weak acids because of its hydroxyl group, which is basic and will neutralize or at least weaken an acid.

Sodium Citrate is primarily used as a flavoring in food, most notably in energy drinks like Rock Star and Red Bull. It was used in the early to mid 20th century as an anticoagulant in blood transfusions, and is still used today in blood banks as a preservative. 

This ingredient is very safe, having been approved by the FDA (Food and Drug Administration), Environment Canada, and the RTECS (The Journal of Pharmacology and Experimental Therapeutics). 

Aminomethyl Propanol

Aminomethyl Propanol consists of an Amine group and a Hydroxyl group attached to a carbon chain.

Both the Amine and the alcohol exhibit Hydrogen bonding.

Aminomethyl Propanol's function in the product is also as a buffer, however it is able to act as a buffer for bases as well as acids. It achieves this function with it's protruding methyl groups, which can freely give out
Hydrogens to neutralize the hydroxides of bases.

Aminomethyl Propanol can also function as an Emulsifier. This means that it allows to normally immiscible liquids to blend.

This chemical is fairly safe. It is classified by the European Union as a minor irritant and as a product with environmental toxicity, but it causes no major health problems.

Propylene Glycol

Propylene Glycol consists of two hydroxyl groups, both of which have hydrogen bonding.

Propylene Glycol functions in the product as a moisturizer. It is ideally suited to this use because of its two hydroxyl groups. Hydroxyl groups are groups that contain a hydroxide molecule, and hydroxide is extremely hydrophilic, meaning it is strongly attracted to water. These hydrophilic groups prevent water from leaving the molecule and allowing it to retain it's moisture.

It's other main use is as a safer alternative to Ethylene Glycol in anti-freeze. It has a variety of additional uses, such as an oil dispersent, a solvent, a food additive, etc. It is produced from propylene oxide using non-catalytic high temperature process at 200 C. 

This product is safe in this usage, as it has been declared safe for skin contact and ingestion in reasonable doses by Environment Canada and the Cosmetics Review board. The ingredient can be dangerous if inhaled however as it was found to cause respiratory problems by the Agency for Toxic Substances and Disease Registry.