**Abstract**

The aim of this work was to identify and quantify formaldehyde present in commercial hair straightening formulations, the application of cosmetovigilance from organoleptic/physicochemical tests and label analysis being approached. Samples A1, A3, A5, and A8 had a formaldehyde concentration ranging from 1.5 to 3.83% (w/v), corresponding to concentrations of 7.5, 16.45, 7.9, and 19.15 times higher than that allowed by the National Agency of Sanitary Monitoring (ANVISA), resulting in strong odor characteristic of this active substance. Of these samples, A3 and A5 did not indicate the presence of formaldehyde on the label besides ignoring the warning information and restrictions of use. The absence of the registration number granted by ANVISA for sample A5, which may be an indication of a clandestine product, was also verified. As to the organoleptic and physicochemical properties, only the A2 sample presented different viscosity and centrifugation results. In view of these results, it was concluded that 50% of the analyzed products were reproved because of the presence of formaldehyde out of the allowed concentration, being evident the importance of the implantation of cosmetovigilance system to guarantee the final quality of the cosmetic products, mainly in view of the safety and efficacy of these products.

**Keywords:** hair straightening, formaldehyde, mandatory labeling

### **1. Introduction**

The beauty market, including toiletries, perfumes, and cosmetics, is one of the fastest growing of all market segments. According to data collected by the Brazilian Association of Personal Hygiene, Perfumes and Cosmetics Industry, Brazil is the third largest sales market with a turnover of approximately R \$ 29.4 billion in 2011 and the world leader in hair straighteners and conditioners, with 37.3 and 18.8% of the market, respectively [1]. Hair is increasingly exhibited as a form of expression and affirmation of the personality, and therefore, the cosmetics market presents a range of products with the resources to treat and embellish them [2]. The progressive brush is a hair straightening procedure, introduced in the Brazilian beauty salons in recent years, which contains formaldehyde in its composition and promises a lasting smoothing, around 1–4 months, becoming a fever in beauty salons [3].

According to the National Agency of Sanitary Monitoring (ANVISA), the incorporation of formaldehyde into the hair straightener is prohibited, as it can cause serious damages to the user of the product and to the professional that applies it, such as irritation, pain, and burn in the skin, injuries in the airways, and irreversible damage to the eyes and hair [4]. Health legislation permits the use of formaldehyde in cosmetic hair products only as a preservative in a maximum concentration of 0.2% and as a nail hardener at a concentration of up to 5%, in accordance with Resolution 15 of 2013 [5].

In order to guarantee the safety and efficacy of cosmetic products, the cosmetovigilance system was created and implemented in Brazil, through Resolution RDC No. 332, dated December 1, 2005 [6]. This resolution was elaborated from the MERCOSUR resolution to the member countries to implement this system, being delegated to the competent national bodies of each associated country [7].

Cosmetovigilance has the function of monitoring the response that the product will cause in the market, analyzing the adverse events caused by cosmetics, identifying the risk involved in the use of these products, and taking pertinent behaviors according to the established cause relationship [8, 9].

Despite the risks and prohibitions, there is a variety of products sold to beauty salons that contain formaldehyde in its composition. These products are used for the hair straightening process, and there seems to be an ignorance of the legislation by hairdressers, providing the indiscriminate use of this substance for this purpose [10]. Therefore, the chapter proposes to identify and measure formaldehyde in commercial formulations of permanent hair straighteners and progressive, as well as evaluating the organoleptic and physicochemical properties and correlate results from the information provided by manufacturers on the labeling of the products, in accordance with the annexes IV and V of DRC 211/2005.
