What are some commonly used chemicals in other semi-permanent hair brands?

We do not include harmful chemicals and synthetic ingredients.  Here are list of just few common ingredients found in other popular semi-permanent hair colors on the market today.

Propylene Glycol

"It's strong enough to dissolve the barnacles off a boat," is how Linda Chae describes this solvent, which is also used in antifreeze and brake fluid. Chae, founder of Chae Organics, Inc points out that factory workers who handle propylene glycol must wear protective gear to prevent skin contact. That's because exposure can cause eye and skin irritation, headaches, nausea, and vomiting.

http://www.shareguide.com/cosmetics.html
http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=240

Methylisothiazolinone / Methylchloroisothiazolinone

Preservative that’s generally recommended for use only in rinse-off products such as cleansers or shampoos. Although used in leave-on products, methylisothiazolinone is known to be sensitizing when used in leave-on products. In fact, the American Contact Dermatitis Society named methylisothiazolinone its Allergen of the Year in 2013! 

As with most ingredients with problematic potential, much depends on the amount used, but, as a general rule, if you see methylisothiazolinone in the middle of an ingredient list for a leave-on product, you should avoid it, particularly if you have sensitive skin or if this preservative is used in conjunction with sunscreen actives like octinoxate or avobenzone. 

Also called MIT, this ingredient is often found in antibacterial products.
Unlike some synthetic chemicals, however, this one isn’t just a mild skin irritant. A recent study found the chemical may actually be linked to nerve damage, and it’s also known to be toxic in several other ways.

http://www.paulaschoice.com/cosmetic-ingredient-dictionary/definition/methylisothiazolinone
http://www.ewg.org/skindeep/ingredient.php?ingred06=703935
http://www.annmariegianni.com/ingredient-watch-list-methylisothiazolinone-the-toxic-ingredient-that-could-cause-nerve-damage/

Methylparaben

Methylparaben is in the paraben family of preservatives used by the food, pharmaceutical, and personal care product industries. Parabens mimic estrogen and can act as potential hormone (endocrine) system disruptors.

http://www.ewg.org/skindeep/ingredient/703937/METHYLPARABEN/#
https://www.truthinaging.com/ingredients/methylparaben

Stearalkonium chloride

First used by the fabric and paper industries as a softener and an anti-static agent, stearalkonium chloride is now commonly found in the cream rinses and conditioners used to soften our tresses. Yet the hard facts on this cationic surfactant show that it is a toxin known to set off allergic reactions. "Although it's a proven irritant, many companies use it in hair conditioning products because it's cheaper and easier to incorporate than proteins or herbals," says Masters.

http://www.shareguide.com/cosmetics.html

DMDM Hydantoin

DMDM Hydantoin is sometimes considered dangerous because of its toxic formaldehyde component, although the percentage is so small that it has been approved safe by the Cosmetic Ingredient Review Expert Panel. It can cause irritation or an allergic reaction on sensitive skin.

DMDM hydantoin is an antimicrobial formaldehyde releaser preservative. People exposed to such formaldehyde-releasing ingredients may develop a formaldehyde allergy or an allergy to the ingredient itself and its decomposition products. In the U.S., approximately 20% of cosmetics and personal care products contain a formaldehyde-releaser and the frequency of contact allergy to these ingredients is much higher among Americans compared to studies in Europe. 

http://www.ewg.org/skindeep/ingredient/702196/DMDM_HYDANTOIN_%28FORMALDEHYDE_RELEASER%29/#
https://www.truthinaging.com/ingredients/dmdm-hydantoin

PEG-100

The Cosmetics Database found PEG 100 Stearate to be a moderate to high hazard ingredient depending on usage. The EWG issues warnings regarding: cancer, developmental and reproductive toxicity, contamination concerns, irritation, and organ system toxicity.

According to a study published in the International Journal of Toxicology, PEGs (including PEG 100 Stearate) can contain harmful impurities, including: Ethylene Oxide, known to increase the incidences of uterine and breast cancers and of leukemia and brain cancer, according to experimental results reported by the National Toxicology Program; 1,4-dioxane, a known carcinogen; PAHs, known to increase the risk of breast cancer; lead; iron; and arsenic.

Products and formulas containing PEG 100 Stearate should not be used on broken or irritated skin. Although PEGs are considered safe for use topically on healthy skin, studies showed that patients suffering from severe burns were treated with PEG-based antimicrobial cream; this treatment resulted in kidney toxicity.

http://davidsuzuki.org/issues/health/science/toxics/chemicals-in-your-cosmetics---peg-compounds-and-their-contaminants/

https://www.truthinaging.com/ingredients/peg-100-stearate
http://www.healthy-communications.com/2006peg_compounds_in_cosmetics.htm