Windex contains harmful chemicals, such as ammonium hydroxide, hexoxyethanol and the chemical's fragrance, according to the Environmental Working Group. The glass cleaner also contains propylene glycol, a controversial substance used in toothpaste and cosmetics. Daily Finance states SC Johnson created a website in March 2009 that elucidates many of the ingredients in the company's cleaning products.
Ammonium hydroxide is a known respiratory irritant that can damage eyesight and the skin. The EWG also states ammonium hydroxide causes acute aquatic toxicity. Hexoxyethanol can affect organs while the fragrance can lead to allergies, skin irritation and nervous system problems. EWG lists Windex as a moderate concern for asthmatics and for those who suffer from respiratory ailments. Skin irritation is another concern scientists have regarding the glass cleaner.
Daily Finance points out Windex uses propylene glycol, a substance deemed safe by the U.S. Environmental Protection Agency. Environmentalist argue that studies show propylene glycol causes kidney and liver damage.
Forbes reports a comprehensive study of household cleaning products, including Windex, came to the conclusion that many products have a broad spectrum of health effects. One of the most noted health effects was asthma while another was endocrine disruption.
The official What's Inside SC Johnson website lists several ingredients of its Windex glass cleaner. Water, isopropyl alcohol, 2-hexoxyethanol, Videt EGM, sodium c14-17 sec-alkyl sulfonate, ammonium hydroxide, propylene glycol, Mirapol Surf S-10, fragrance and Liquitint Sky Blue Dye are all in a bottle of Windex.