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What do we need to know about hair straightening?
Abstract
p class="abstract"> Hair straightening is a popular hair procedure. The first hair straightening products were used for African hair. Various modes of hair straightening methods are currently being used. Temporary methods like blow drying and ironing are used for easy manageability of hair, both by modern men and women. Salon- based hair straighteners were initially permanent relaxers which, with time, evolved to formaldehyde-free hair strengthening procedures like hair Botox which is currently in trend. It improves hair manageability, increases hair strength and reduces frizz without producing much chemical damage to hair and by maintaining their natural waves, thereby producing a more natural look. We performed a thorough literature search on the topic in PubMed, consulted various hair stylists and beauty school professors prior to formulation of this article. The article aims at understanding the basic mechanisms involved in various hair straightening methods which helps us to advice patients on a wholesome care of hair. </p
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Introduction: In the last few years, smoothing hair treatments has taken the Saudi cosmetic industry by storm, all containing various levels of formaldehyde, a classified carcinogen by The World Health Organization (WHO), International Agency for Research on Cancer (IARC), United States Environmental Protection Agency (EPA) and Oregon Occupational Safety and Health Division (Oregon OSHA). With the lack of studies –in Saudi Arabia and worldwide- the level of public awareness and their malpractice is questionable. Materials and Methods: Online and paper self-administered questionnaires were distributed over 1039 females. Including questions assessing knowledge on hair treatments, previous experiences and side effects. Results: (60%) of participant had a poor knowledge score. When asked if formaldehyde is a carcinogen, (70.5%) did not know and (5.1%) answered incorrectly. (33.5%) of participants had done hair treatments before, but (52.3%) didn't read about them prior. The major motive was to facilitate hair management (76.1%). (57.5%) of participants said their hair wasn't examined before the treatment, and only (31%) applied scalp barriers. Flat irons were used in most cases (83.6%). Most importantly, (55.2%) did not know if the product used contains formaldehyde, and (15.2%) used formaldehyde-containing products. The majority (74.7%) reported having side effects, mostly hair fall (56.9%) and dandruff (30.5%). When asked if they would consider using hair treatments again, (61.2%) said no, mainly because of the damage and side effects (90.6%). Limitations: Majority of participants being from the central region of Saudi Arabia and the limited older age group (9.6%). Conclusion: Recently, in 2016, the Saudi Food and Drug Authority published a warning article on four products found in local markets containing high levels of formaldehyde. This shows the lack of industrial supervision and consumers protection and the need of strict monitoring regimens in stores and beauty salons. Future studies should be applied in assessing the public's misconceptions and practices, along with campaigns and social media efforts to raise the overall knowledge.
Background
Chemical hair straightening becomes popular for managing frizzy hair. Keratin in hair care products can penetrate the cortex of the hair fiber improving the mechanical properties of damaged fibers and promote a surface coating that prevents or decreases water diffusion through the hair fibers. This may have beneficial effects on the hair structure; however, the side effects and safety of this treatment have not yet been completely evaluated.
Aims
To evaluate the efficacy and safety of chemical hair straightening application on the hair shaft.
Subjects and Methods
Thirty female subjects older than 15 years with hair curl types III–V were included. They were subjected to full history taking and dermatologic examination of hair and scalp prior to and after application of chemical hair straightener. To detect the presence of transverse fissures, split ends, or possible side effects, the distal 3‐5 cm of hair fibers were cut before and after the last step of chemical hair straightener application for light microscopy examination. Three randomly selected samples were examined by transmission electron microscope.
Results
Chemical hair straightening led to significant decrease in the degree of hair curl and increased hair smoothness and shine. The treated hair fibers showed significant repair of the broken cuticle (P < 0.001), while no significant improvement was observed regarding transverse fissures or split ends (P 0.60 and 0.74, respectively).
Conclusion
Although chemical hair straightening application has a beneficial effect on hair shafts, some side effects may occur after. Hence, it is necessary to develop a more safe tool.
Hair chemical treatments, such as dyeing and straightening products, are known to cause damage that can be assessed by protein loss.
The aim of this study was to evaluate the hair protein loss caused by combined chemical treatments (dye and relaxer) using the validated bicinchoninic acid (BCA) method. Three kinds of straighteners, based on ammonium thioglycolate, guanidine hydroxide and sodium hydroxide, were evaluated and the least harmful combination indicated.
Caucasian virgin dark brown hair tresses were treated with developed natural brown color oxidative hair dyeing and/or straightening commercial products based on ammonium thioglycolate, sodium hydroxide, or guanidine hydroxide. Protein loss quantification was assessed by the validated BCA method which has several advantages for quantifying protein loss in chemically treated hair.
When both treatments (straightening and dyeing) were combined, a higher negative effect was observed, particularly for dyed hair treated with sodium hydroxide. In this case, a 356% increase in protein loss relative to virgin hair was observed and 208% in relation to only dyed hair. The combination of dying and relaxers based on ammonium thioglycolate or guanidine hydroxide caused a small increase in protein loss, suggesting that these straightening products could be the best alternatives for individuals wishing to combine both treatments.
These results indicated that when application of both types of products is desired, ammonium thioglycolate or guanidine hydroxide should be chosen for the straightening process.
© 2015 Wiley Periodicals, Inc.
In 2004, the International Agency for Research on Cancer (IARC) reclassified formaldehyde (FA) from a probable (Group 2A) to a known human carcinogen (Group 1) citing results for nasopharyngeal cancer (NPC) mortality from the follow-up through 1994 of the National Cancer Institute formaldehyde cohort study. To the contrary, in 2012, the Committee for Risk Assessment of the European Chemicals Agency disagreed with the proposal to classify FA as a known human carcinogen (Carc. 1A), proposing a lower but still protective category, namely as a substance which is presumed to have carcinogenic potential for humans (Carc. 1B). Thus, U.S. and European regulatory agencies currently disagree about the potential human carcinogenicity of FA.
In 2013, the National Cancer Institute reported results from their follow-up through 2004 of the formaldehyde cohort and concluded that the results continue to suggest a link between FA exposure and NPC. We discuss in this commentary why we believe that this interpretation is neither consistent with the available data from the most recent update of the National Cancer Institute cohort study nor with other research findings from that cohort, other large cohort studies and the series of publications by some of the current authors, including an independent study of one of the National Cancer Institute’s study plants.
Another serious concern relates to the incorrectness of the data from the follow-up through 1994 of the National Cancer Institute study stemming from incomplete mortality ascertainment. While these data were corrected by the National Cancer Institute in subsequent supplemental publications, incorrect data from the original publications have been cited extensively in recent causal evaluations of FA, including IARC. We conclude that the NCI publications that contain incorrect data from the incomplete 1994 mortality follow-up should be retracted entirely or corrected via published errata in the corresponding journals, and efforts should be made to re-analyze data from the 2004 follow-up of the NCI cohort study.
Objective:
To investigate the association between maternal exposure to hair dyes and hair straightening cosmetics (HDSC) during pregnancy and leukemia at an early age (<2yr., EAL).
Methods:
A multicenter hospital-based case-control study was carried out in 13 states in Brazil between 1999 and 2007. Mothers of 176 ALL (acute lymphocytic leukemia) and 55 AML (acute myeloid leukemia) cases and 419 controls were enrolled and interviewed. Data on maternal exposure to HDSC occurring 3months before pregnancy, during pregnancy and during breastfeeding were obtained. Data were also gathered on paternal exposure to HDSC before pregnancy. Unconditional logistic regression was performed and odds ratios (OR) on the association between HDSC use and EAL were obtained after adjustment for hormonal intake during pregnancy, maternal age, education, birth weight, and the child skin color.
Results:
An adjusted OR of 1.78 (95% C.I. 1.13-2.81) was observed between maternal exposure to HDSC in the first trimester of pregnancy and ALL. Regarding AML, an adjusted OR of 2.43 (95% C.I. 1.13-5.22) was found for maternal exposure to HDSC during breastfeeding. No association between maternal exposure to HDSC during pregnancy and ALL or AML was observed in children with MLL (Mixed Lineage Leukemia) gene rearrangement.
Conclusions:
Results in this study seem to support the hypothesis that maternal exposure to HDSC during pregnancy may be involved in the etiology of leukemia in children under 2years of age.
Hair plays an important role in one's personality and builds confidence. Now-a-days, chemical hair relaxers are used very commonly in the society. We document the adverse effects reported by the sample that have used any one of the professional chemical hair relaxers.
To study the adverse effects reported by the sample who underwent repeated chemical hair relaxing.
Cross-sectional questionnaire based study done on a sample taken from a medical college and hospital campus in Mangalore.
The sample was restricted to females and to those who underwent it more than once. A questionnaire was given to a sample of 90, which matched our criteria.
SPSS software 17.
Adverse effects reported by the sample after undergoing the procedure were found to be a high 95.56%, out of which the following are the common adverse effects reported; frizzy hair in 67%, dandruff in 61%, hair loss in 47%, thinning and weakening of hair in 40%, greying of hair 22%, and split ends in only 17%.
Very few studies have been conducted on the adverse effects of hair straightening products in India. From our study, it can be stated that most of the samples had adverse effects, which was as high as 95.56%. Hence from the details elicited from this study, we can conclude that, usage of chemical hair relaxers does cause adverse effects and is "not a myth." Thus, it is necessary to make available a less harmful chemical hair relaxer to the society.
Hair dryers are commonly used and can cause hair damage such as roughness, dryness and loss of hair color. It is important to understand the best way to dry hair without causing damage.
The study assessed changes in the ultra-structure, morphology, moisture content, and color of hair after repeated shampooing and drying with a hair dryer at a range of temperatures.
A standardized drying time was used to completely dry each hair tress, and each tress was treated a total of 30 times. Air flow was set on the hair dryer. The tresses were divided into the following five test groups: (a) no treatment, (b) drying without using a hair dryer (room temperature, 20℃), (c) drying with a hair dryer for 60 seconds at a distance of 15 cm (47℃), (d) drying with a hair dryer for 30 seconds at a distance of 10 cm (61℃), (e) drying with a hair dryer for 15 seconds at a distance of 5 cm (95℃). Scanning and transmission electron microscopy (TEM) and lipid TEM were performed. Water content was analyzed by a halogen moisture analyzer and hair color was measured with a spectrophotometer.
Hair surfaces tended to become more damaged as the temperature increased. No cortex damage was ever noted, suggesting that the surface of hair might play a role as a barrier to prevent cortex damage. Cell membrane complex was damaged only in the naturally dried group without hair dryer. Moisture content decreased in all treated groups compared to the untreated control group. However, the differences in moisture content among the groups were not statistically significant. Drying under the ambient and 95℃ conditions appeared to change hair color, especially into lightness, after just 10 treatments.
Although using a hair dryer causes more surface damage than natural drying, using a hair dryer at a distance of 15 cm with continuous motion causes less damage than drying hair naturally.
Brazilian keratin treatment (BKT) is a prevalent hair straightening method widely used by women in the world. The degree of concentration of formaldehyde safe for sensitive patients is still obscure. Report claims that these products contain intolerably high levels of formaldehyde. Yet, hair straightening products may lead to severe allergic contact dermatitis, by means of the responsible allergens such as formaldehyde and its releasers. This case report presents the case of a 37‐year‐old female patient developing extensive edema of the face and acute inflammatory changes in the scalp from chemical‐induced irritation, on the day following the application of BKT to straighten her hair.
Hair straitening products are widely used by hairstylists. Many keratin-based hair smoothing products contain formaldehyde. This study aimed to investigate occupational formaldehyde exposure among hairstylists dealing with hair straightening products and the relation between genotoxicity biomarkers and the short-term formaldehyde exposure concentrations and the working years. The study was carried out in Cairo, Egypt on 60 hairstylists use hair straightening products divided into two groups according to the working years. All hairstylists were subjected to micronucleus (MN) frequencies in both epithelial buccal cells (EBC) and peripheral blood lymphocytes (PBL). Fifteen-minute (min) formaldehyde exposure concentrations were measured at workplace during hair straightening procedure. Fifteen-minute formaldehyde concentrations in both groups exceeded the National Institute for Occupational Safety and Health and the American Conference of Governmental Industrial Hygienist thresholds levels. The MN frequencies in EBC and PBL showed a significant increase in group II in comparison to control and group I, which in turn showed a significant increase in MN frequency in PBL and a nonsignificant increase in the MN frequency in EBC when compared to control. A positive correlation was found between genotoxicity biomarkers and working years. Occupational exposures to hair straightening products in the studied hairstylist were found to expose them to formaldehyde concentrations that exceeded the standard limits. All selected genotoxicity biomarkers showed a significant increase in exposed workers and were positively correlated to the duration of exposure.
Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity.
Objective:
To study prenatal air toxic exposure and Wilms' tumor in children.
Methods:
We identified 337 Wilms' tumor cases among children younger than 6 years (1988 to 2008) from the California Cancer Registry, randomly selected 96,514 controls from California birth rolls in 20:1 ratio matched to all cancer cases, then linked birth addresses to air monitors within 15 miles to assess exposures. Multiple logistic regressions were applied to estimate effects.
Results:
Children prenatally exposed to formaldehyde, polycyclic aromatic hydrocarbons, perchloroethylene, or acetaldehyde in the third trimester had an increased odds of Wilms' tumor per interquartile increase in concentration (odds ratio [95% confidence interval]: 1.28 [1.12 to 1.45], 1.10 [0.99 to 1.22], 1.09 [1.00 to 1.18], 1.25 [1.07 to 1.45], respectively).
Conclusions:
We found positive associations for four air toxics. This is the first study of this kind. Future studies are needed to confirm our findings.
Synopsis
Personal image, as it relates to external beauty, has attracted much attention from the cosmetic industry, and capillary aesthetics is a leader in consumption in this area. There is a great diversity of products targeting both the treatment and beautification of hair. Among them, hair straighteners stand out with a high demand by costumers aiming at beauty, social acceptance and ease of daily hair maintenance. However, this kind of treatment affects the chemical structure of keratin and of the hair fibre, bringing up some safety concerns. Moreover, the development of hair is a dynamic and cyclic process, where the duration of growth cycles depends not only on where hair grows, but also on issues such as the individual's age, dietary habits and hormonal factors. Thus, although hair fibres are composed of dead epidermal cells, when they emerge from the scalp, there is a huge variation in natural wave and the response to hair cosmetics. Although it is possible to give the hair a cosmetically favourable appearance through the use of cosmetic products, for good results in any hair treatment, it is essential to understand the mechanisms of the process. Important information, such as the composition and structure of the hair fibres, and the composition of products and techniques available for hair straightening, must be taken into account so that the straightening process can be designed appropriately, avoiding undesirable side effects for hair fibre and for health. This review aims to address the morphology, chemical composition and molecular structure of hair fibres, as well as the products and techniques used for chemical hair relaxing, their potential risk to hair fibre and to health and the legal aspects of their use.
Synopsis
A peptide based on a fragment of hair keratin type II cuticular protein, keratin peptide (KP), was studied as a possible strengthening agent for weakened relaxed hair. The peptide was prepared both in aqueous water formulation (WF) and organic solvent formulations (OF), to determine the effect of organic solvents on peptide interaction with hair and the differences in hair recovery. Both peptide formulations were shown to improve mechanical and thermal properties of weakened hair with peptide in OF showing the stronger effect. As a potential new hair care product, and so would necessitate contact with skin, the cytotoxicity and genotoxicity of the peptide were also evaluated through different methodologies (Alamar Blue assay, 2′‐7′‐dichlorofluorescein probe, cell morphology and growth and evaluation of DNA damage by an alkaline version of the comet assay) in skin fibroblasts. These tests are indicators of the potential of peptide to cause irritation on skin or to be carcinogenic, respectively. The peptide in WF did not cause cytotoxicity or genotoxicity in any of the concentrations tested. The presence of OF, however, induced a 20% decrease in cell viability in all of the range of concentrations used after 72‐h incubation. Moreover, OF inhibited cell growth and was considered genotoxic at first contact with cells. The peptide was therefore considered a promising strengthening agent for hair and was shown to be innocuous when applied in WF.
Cosmetic hair care products are often implicated by the user or the clinician in cases of hair loss. Yet, these products are used ad lib, in a wide variety of home conditions and on a wide variety of hair types, by millions of consumers every day with no adverse effects. Based on this extensive data set, the absence of literature reports, and a detailed understanding of the mode of action of cosmetic hair care products, we can conclude that they do not cause hair loss. Clinicians investigating cases of hair loss must fully appreciate the hair cycle, the length of time a single fibre may be present on the head, and its biological and cosmetic history in order to understand the causes of hair loss and make the correct diagnosis. With a better understanding of the cosmetic practices used by everyday consumers, the clinician will be in a strong position to help patients re-grow their hair and guide them through a high quality hair care regime.
Afro-ethnic hair, when compared with naturally straight hair, presents some important variations such as differences in diameter in many points of the thread, ellipsoidal threads, and low trend of hydrating the scalp thus turning the hair drier, because the natural sebum distribution is irregular along the thread. This kind of hair may be straightened through both chemical and thermal methods. Straightening is a chemical process by which excessively curly hair is straightened in an irreversible way. Generally, the products used are formulated in a cosmetic emulsion with high pH. In this review, we present the historical development of hair straightening or relaxing through the evolution of the product categories.
Hair relaxers (straighteners) have been used by millions of African American women, often for many years. Relaxer ingredients can enter the body through scalp lesions and burns. Because manufacturers are not required to list all ingredients, these products may contain unknown harmful substances. We assessed hair relaxer use in relation to breast cancer incidence in the Black Women's Health Study, a nationwide follow-up study of African American women. Information on hair relaxer use was collected in 1997; 48,167 women were followed subsequently through 2003 for incident breast cancer. Incidence rate ratios of breast cancer were estimated with Cox regression. During 266,298 person-years of follow-up, 574 incident cases of breast cancer were ascertained. There were no increases in breast cancer risk associated with any categories of duration of hair relaxer use, frequency of use, age at first use, number of burns experienced during use, or type of relaxer used. The incidence rate ratio for use at least seven times a year for 20 or more years relative to use for less than a year was 0.98 (95% confidence interval, 0.78-1.39). These results suggest that hair relaxer use does not increase the incidence of breast cancer in African American women.
Glyoxylic acid, a small dicarboxylic acid, has been detected at measurable levels in the atmosphere and is suspected to be present in indoor air environments. It is generated through the ozonolysis of several high volume production compounds that are commonly found indoors. Glyoxylic acid was tested in a combined irritancy and local lymph node assay (LLNA). It tested positive in the LLNA with an EC3 value of 5.05%. Significant increases were observed in the B220+cell population in the draining lymph nodes. No changes were identified in the IgE+B220+ cell population in the draining lymph nodes or total serum IgE levels; this suggests that glyoxylic acid functions as a T-cell-mediated contact sensitizer. Exposure to volatile organic compounds (VOC), similar to glyoxylic acid, emitted from building materials, cleaning formulations or other consumer products, and /or indoor chemistry have been linked to adverse health effects. These results may provide an explanation for some of adverse health effects associated with indoor air exposure.
To evaluate the genotoxic risk to hairdressers exposed daily to chemical substances such as hair dyes, waving and straightening preparations and manicurists' products by the Comet assay test (single-cell gel electrophoresis).
The Comet assay was performed on blood samples from 69 female hairdressers (36.4 +/- 10.7 years old) currently employed in 21 different beauty institutes in São Paulo, Brazil, and on 55 female control blood donors (32.6 +/- 10.0 years old) from the São Paulo University Clinical Hospital blood bank. All the control subjects had occupations other than hairdresser. Comet assays were performed by evaluating 100 blood lymphocytes per individual and graded by visual score according to comet tail length.
The hairdressers showed a higher frequency of DNA damage revealed by Comet Score (159.8 +/- 71) when compared to the control group (125.4 +/- 64.1), and the difference was statistically significant by the Student's t-test (P = 0.005). Multiple regression analysis showed that in addition to the hairdressers' profession, tobacco use contributed to the higher frequency of cells with comets (P < 0.05).
The observed DNA damage could be associated with the hairdressers' occupational environment, where different chemicals are chronically manipulated and inhaled. Considering that this profession in many countries, including Brazil, is not officially regulated, more attention should focus on these professionals not only by legislative bodies but also by multidisciplinary teams able to develop and implement risk prevention and control strategies for chemical, physical and biological agents to which hairdressers are exposed.
Impact of acid straightener's pH value in the hair fiber properties
- A M Goshiyama
- M F Dario
- Crrc Lima
- Glb De Araújo
- A R Baby
- Mvr Velasco
Goshiyama AM, Dario MF, Lima CRRC, de Araújo
GLB, Baby AR, Velasco MVR. Impact of acid
straightener's pH value in the hair fiber properties. J
Cosmet Dermatol. 2020;19(2):508-13.