Hair straightening is a hair styling technique used since the 1890s involving the flattening and straightening of hair in order to give it a smooth, streamlined, and sleek appearance. [1] It became very popular during the 1950s among black males and females of all races. It is accomplished using a hair iron or hot comb, chemical relaxers, Japanese hair straightening, [2] Brazilian hair straightening, or roller set/blowdryer styling. In addition, some shampoos, conditioners, and hair gels can help to make hair temporarily straight.
The process is often called "rebonding" in some countries from Southeast Asia (e.g. Indonesia, Singapore, Malaysia and Philippines). If done often, flat irons and chemicals can be damaging to hair. [3] Excessive straightening often results in split ends. [3] However, heat protectant sprays can decrease the damage. [3]
Hair irons and hot combs used appropriately temporarily modify the shape and texture of hair. The hair will tend to revert to its original form due to environmental factors, mainly contact with water from washing, rain, humidity, etc. This includes water in styling products such as gels applied after straightening, although careful use of such treatments can produce usable results.
Use of too much heat, or for too long, can cause heat damage, irreversibly altering the hair's structure. Use of protective sprays or lotions before heat styling may help to prevent heat damage. While the damage cannot be reversed, it can be disguised using various styling techniques. Only cutting off and regrowing damaged hair removes the damage. [4] [5] [6]
There are five principal tools used for hair straightening without chemical treatment:
A popular temporary straightening method is the Dominican blowout which originated in the Dominican Republic. The technique spread to the United States where it was popularized by Dominican stylists. The Dominican blowout allows highly-textured and tightly-curled hair types to be straightened without the use of chemicals. It has become popular, particularly among African Americans, as an alternative to permanent hair straightening or as a method of straightening the hair between relaxers. [8]
Relaxers and the other methods permanently alter the structure of the hair, although new hair growth is not affected. The drug interferon alpha has been reported as being shown to modify hair follicles causing permanent change in a person's hair texture. [9] Chemical hair straightening uses chemical substances to break disulfide bonds, also called an S-S bond or disulfide bridge, in the hair shaft. [10] [11]
There are several ways of permanently straightening hair. The main methods used today are:
Keratin/Brazilian treatment | Japanese/Thermal treatment | Chemical straightening/ hair relaxing treatment | |
---|---|---|---|
method | keratin layer + flat ironing | bond breaking chemical + heat + neutralising chemical | hydroxide substance to break the disulfide bonds |
texture & appearance | soft, silky, shiny, easy to manage. Lasts 2-6 months. | silky straight hair. Permanent. | soft, straight, easy to manage. Permanent. |
suitable for | all hair types, damaged and previously treated | hair that has not been treated with chemicals before; loose to medium curls | coarse, tight curls |
safety concerns |
|
|
|
duration of treatment | 2-4 hours | 4-8 hours | varies |
recommended hair care |
|
| deep conditioning |
Relaxers can contain carcinogens such as formaldehyde-releasing agents, phthalates, and other endocrine-disrupting compounds, [12] according to National Institutes of Health studies. The compounds can mimic the body's hormones, and studies have found them to be linked to breast, uterine, and ovarian cancers. For example, a 2017 study found that women who used chemical relaxers were nearly twice as likely to develop breast cancer as those who did not. [13] [14] [15]
Hair straightening using a hot comb or relaxer has a long history among women and men of African American descent, reflected in the huge commercial success of the straightening comb popularized by Madam C. J. Walker and other hairdressers in the early 1900s. [16] The Madam Walker System of Beauty Culture focused more on hygiene and healthy scalps and hair than hair straightening. Her vegetable shampoo and Madam Walker's Wonderful Hair Grower (an ointment that contained sulfur) were designed to heal dandruff and severe scalp infections that were very common during a time when most Americans lacked indoor plumbing, electricity and central heating. Walker did not invent the hot comb, which was commercially available in Europe and America as early as the 1870s. While the practice has at times been a controversial issue in discussions of racial identity, visits to the hair salon have become embedded in black culture, fulfilling an important social role especially for women. [17] [18]
A hairstyle, hairdo, haircut or coiffure refers to the styling of hair, usually on the human head but sometimes on the face or body. The fashioning of hair can be considered an aspect of personal grooming, fashion, and cosmetics, although practical, cultural, and popular considerations also influence some hairstyles.
A hairbrush is a brush with rigid or soft spokes used in hair care for smoothing, styling, and detangling human hair, or for grooming an animal's fur. It can also be used for styling in combination with a curling iron or hair dryer.
Hair conditioner is a hair care cosmetic product used to improve the feel, texture, appearance and manageability of hair. Its main purpose is to reduce friction between strands of hair to allow smoother brushing or combing, which might otherwise cause damage to the scalp. Various other benefits are often advertised, such as hair repair, strengthening, or a reduction in split ends.
A hair iron or hair tong is a tool used to change the arrangement of the hair using heat. There are three general kinds: curling irons, used to make the hair curly, straightening irons, commonly called straighteners or flat irons, used to straighten the hair, and crimping irons, used to create crimps of the desired size in the hair.
A permanent wave, commonly called a perm or permanent, is a hairstyle consisting of waves or curls set into the hair. The curls may last a number of months, hence the name.
Trichorrhexis nodosa is a defect in the hair shaft characterized by thickening or weak points (nodes) that cause the hair to break off easily. This group of conditions contributes to the appearance of hair loss, lack of growth, and damaged-looking hair.
A hot comb is a metal comb that is used to straighten moderate or coarse hair and create a smoother hair texture. A hot comb is heated and used to straighten the hair from the roots. It can be placed directly on the source of heat or it may be electrically heated.
A relaxer is a type of lotion or cream generally used by people with tight curls or very curly hair which makes hair easier to straighten by chemically "relaxing" the natural curls. The active agent is usually a strong alkali, although some formulations are based on ammonium thioglycolate or formaldehyde.
Artificial hair integrations, more commonly known as hair extensions, hair weaves, and fake hair add length and fullness to human hair. Hair extensions are usually clipped, glued, or sewn on natural hair by incorporating additional human or synthetic hair. These methods include tape-in extensions, clip-in or clip-on extensions, micro/nano rings, fusion method, weaving method, and wigs.
Hair care or haircare is an overall term for hygiene and cosmetology involving the hair which grows from the human scalp, and to a lesser extent facial, pubic and other body hair. Hair care routines differ according to an individual's culture and the physical characteristics of one's hair. Hair may be colored, trimmed, shaved, plucked or otherwise removed with treatments such as waxing, sugaring and threading. Hair care services are offered in salons, barbershops and day spas, and products are available commercially for home use. Laser hair removal and electrolysis are also available, though these are provided by licensed professionals in medical offices or speciality spas.
Trichoptilosis, schizotrichia, and informally split ends, is the splitting or fraying of the hair-shaft due to excessive heat and mechanical stress.
Kinky hair, also known as afro-textured hair, is a human hair texture prevalent in the indigenous populations of many regions with hot climates, mainly sub-Saharan Africa, Melanesia, and Australia. Each strand of this hair type grows in a repeating pattern of small contiguous kinks. These numerous kinks make kinky hair appear denser than straight, wavy, and curly hair types.
Uncombable hair syndrome (UHS) is a rare structural anomaly of the hair with a variable degree of effect. It is characterized by hair that is silvery, dry, frizzy, wiry, and impossible to comb. It was first reported in the early 20th century. It typically becomes apparent between the ages of 3 months and 12 years. UHS has several names, including pili trianguli et canaliculi (Latin), cheveux incoiffables (French), and "spun-glass hair". This disorder is believed to be autosomal recessive in most instances, but there are a few documented cases where multiple family members display the trait in an autosomal dominant fashion. Based on the current scientific studies related to the disorder, the three genes that have been causally linked to UHS are PADI3, TGM3, and TCHH. These genes encode proteins important for hair shaft formation. Clinical symptoms of the disorder arise between 3 months and 12 years of age. The quantity of hair on the head does not change, but hair starts to grow more slowly and becomes increasingly "uncombable". To be clinically apparent, 50% of all scalp hair shafts must be affected by UHS. This syndrome only affects the hair shaft of the scalp and does not influence hair growth in terms of quantity, textural feel, or appearance on the rest of the body.
Brazilian hair straightening is a semi-permanent hair straightening method done by temporarily sealing a liquid solution consisting of formaldehyde or a formaldehyde derivative and a preservative solution into the hair with a hair iron.
Bubble hair deformity is damage of the hair shaft, resulting in patches of short weak brittle hair, that feels rough.
Hairstyling tools may include hair irons, hair dryers, hairbrushes, hair rollers, diffusers and various types of scissors.
African-American hair or Black hair refers to hair types, textures, and styles that are linked to African-American culture, often drawing inspiration from African hair culture. It plays a major role in the identity and politics of Black culture in the United States and across the diaspora. African-American hair often has a kinky hairy texture, appearing tightly coiled and packed. Black hair has a complex history, culture, and cultural impact, including its relationship with racism.
The natural hair movement is a movement which aims to encourage people of African descent to embrace their natural, afro-textured hair; especially in the workplace. It originated in the United States during the 1960s, and resurged in popularity in the 2000s.
The Curly Girl Method is an approach to hair care designed by author Lorraine Massey for natural hair that has not been chemically relaxed. This method discourages the daily use of sulfate shampoo, which is considered too harsh for curly hair. Among other things, it calls for the use of a cleansing conditioner in place of shampoo, no silicones, the use of a diffuser when blowdrying, and no combs, brushes, or terrycloth towels. It also includes tips for using hair gel and other styling products. The aim in general is to treat naturally curly hair gently, minimizing damage to the hair cuticle; to keep it moisturized, since curly hair is more prone to dryness than straight hair; and, perhaps most significantly, to accentuate rather than interfere with the hair's natural curl pattern.
Frizz is hair that does not align with the surrounding hair, but stands up or curls independently, creating a fuzzy or irregular texture. The three main causes of frizz are genetics, hair damage, and humidity. Frizzy hair can be seen as a positive or a negative trait depending on the current fashion and one's personal preference. Many hair products, such as gels, pomades, and hair waxes, are designed to reduce frizz.