p-Phenylenediamine is one of the simplest aromatic diamine primarily used as a component of engineering polymers, composites, dye intermediate and as a hair dye. p-Phenylenediamine is easily oxidized, and for this reason derivatives of p-Phenylenediamine are used as antiozonants in the production of rubber products. The substituents, naphthyl, isopropyl etc. affect the effectiveness of their antioxidant roles as well as their properties as skin irritants. Acute (short-term) exposure to high levels of p-phenylenediamine may cause severe dermatitis, eye irritation and asthma, gastritis, renal failure, vertigo, tremors, convulsions, and coma in humans. Eczematoid contact dermatitis may result from chronic (long-term) exposure in humans. In rats and mice chronically exposed to p-phenylenediamine in their diet, depressed body weights, but no other clinical signs of toxicity were observed in several studies. No information is available on the reproductive, developmental, or carcinogenic effects of p-phenylenediamine in humans. EPA has not classified p-phenylenediamine with respect to carcinogenicity.

Benzylparaben (BzP), a type of parabens being used as a preservative agent in cosmetics, food, and pharmaceutical products. It is an allergic compound, which was shown to fit well into the agonist pocket of human estrogen receptor α (hERα).

N,N'-Diphenyl-p-phenylenediamine is used as an antioxidant and/or stabilizer for rubber, petroleum oils and feedstuffs. It is also used as a polymerization inhibitor and a retardant against copper degradation. It is a chemical intermediate to make dyes, drugs, plastics and detergent additives.

Morpholinylmercaptobenzothiazole is a chemical allergen, it is used in the vulcanization of rubber. It is used for diagnosis of contact allergy. It is a component of Mercapto Mix, used in the epicutaneous patch test, called T.R.U.E. TEST, approved by FDA in 1994. T.R.U.E. TEST is indicated for use as an aid in the diagnosis of allergic contact dermatitis in persons 18 years of age and older whose history suggests sensitivity to one or more of the 35 substances included on the T.R.U.E. TEST panels.

Diphenylguanidine (DPG) has been used as a primary and secondary accelerator in the vulcanization of rubber. Exposure to DPG may occur as a result of dermal contact during rubber manufacture or from contact with the finished products. DPG is poorly absorbed through skin. It can be found in latex gloves and other rubber products found in homes and offices. Diphenylguanidine is a standardized chemical allergen. It is used for diagnosis of contact allergy. It is a component of Carba Mix, used in the epicutaneous patch test, called T.R.U.E. TEST, approved by FDA in 1994. T.R.U.E. TEST is indicated for use as an aid in the diagnosis of allergic contact dermatitis in persons 18 years of age and older whose history suggests sensitivity to one or more of the 35 substances included on the T.R.U.E. TEST panels.

Tetramethylthiuram monosulfide (TMTM) is used as a secondary accelerator and activator in the processing of natural and butyl rubbers. It is used as a fungicide, and insecticide.

2,2'-dithiobisbenzothiazole is a Standardized Chemical Allergen as labeled by US Food and Drug Administration. and can cause an allergic contact dermatitis.Its physiologic effect is by means of increased histamine release, and cell-mediated immunity. 2,2'-dithiobis(benzothiazole) is a useful compound in the rubber industry as a vulcanization accelerator. 2,2'-dithiobis(benzothiazole) was marketed to the rubber industry under the tradename Altax(TM) by the R. T. Vanderbilt Company, Inc. and was originally developed for safe processing of rubber compounds cured at above 142° C. 2,2'-dithiobis(benzothiazole) is widely used in compounds of all types for many major commercial applications. It may be carcinogenic for human. The mortality (1955-2005) and cancer morbidity experience (1971-2005) of a cohort of 363 male production workers exposed to MBT while employed at a chemical factory in north Wales showed a significant excess mortality for cancers of the large intestine.

Bronopol is used as a preservative in various cosmetic, pharmaceutical, toiletry and household preparations at concentrations of up to 0.1% (wt/vol) particularly because of its high activity against Gram-negative bacteria, especially Pseudomonas aeruginosa and other pseudomonad. Bronopol hydrolyzes within 3 h at 60 °C and pH 8, producing formaldehyde, nitrosamines, and other molecules. Although the parent compound (bronopol) is rather short-lived in the environment, its degradation products are toxic and more persistent. The protection against the bactericidal activity of bronopol afforded by catalase or superoxide dismutase suggests that the activity stems from the aerobic interaction and the generation of active oxygen species from oxygen diffusing into the suspensions during bronopol treatment. The acute oral LD50 was 307 mg/kg for rat males and 342 mg/kg for females. Bronopol is moderately toxic by the oral route. Results from an acute dermal toxicity study while inadequate, suggest bronopol is highly toxic by the dermal route.

Imidurea (Imidazolidinyl urea) is used as an antimicrobial agent and preservative in cosmetics and toiletries. It is very active against gram and gram- bacteria as a synergist in combination with parabens. Imidazolidinyl urea is more active against bacteria than fungi and is often combined with parabens to provide a broad spectrum preservative system. This preservative is one of the most widely used preservative systems in the world. The Food and Drug Administration (FDA) considers imidazolidinyl urea as one of the most common antimicrobial agents used in cosmetics. Due to its high water solubility, imidazolidinyl urea can be incorporated into almost all water-based cosmetics, toiletries, and cold mix formulations. It is present in a wide range of liquid and powder products such as baby lotion, skin cream, sunscreens, shampoos, eyeliners, blush, perfumes, deodorants, hair dyes, shaving cream, and face masks. Imidazolidinyl urea is permitted for use in personal care products in the European Union at a maximum concentration of 0.6%. In Japan, imidazolidinyl urea is allowed in rinse-off cosmetics such as shampoo, body wash, and facial cleanser at a maximum concentration of 0.3%. Imidurea is an ingredient of FDA-approved NIZORAL® (ketoconazole) 2% Shampoo, indicated for the treatment of tinea (pityriasis) versicolor caused by or presumed to be caused by Pityrosporum orbiculare (also known as Malassezia furfur or M. orbiculare).

Cinnamaldehyde is one of the active compounds found in cinnamon. It was reported that cinnamaldehyde has anti-diabetic, anti-cancer, antimicrobial and anti-inflammatiry activity. Cinnamon is a common prescription compound in traditional Chinese medicine and it is used as a dietary supplement all over the world. Cinnamon dietary supplement Cinnamonforce (min. 35% cinnamaldehyde) was tested in phase II clinical trials and demonstrated therapeutic activity in patients with type 2 diabetes. The mechanism of cinnamaldehyde possibly involves the activation of PPAR gamma/delta receptors. Cinnamaldehyde is partially metabolized into cinnamic acid in the stomach and small intestine, and is almost completely metabolized into cinnamic acid in the liver. Cinnamic acid is believed to be the active metabolite, which is responsible for anti-diabetic properties of cinnamaldehyde.