All posts by lisa01pd2014

Hair Die?

Since I was a kid, I’ve always been fascinated with hair dyes and have always dreamed of having my hair dyed purple. However, I’ve always heard people say that hair dye is very bad for one’s hair but I’ve never really thought about the chemistry behind it. So my question is: to what extent is hair dye safe for us to use?

In order to fully understand how hair dye works, I first asked myself: how exactly does hair colouring work? Hair colouring works when chemical reaction occurs between the hair molecules and pigments with peroxide and ammonia found in the hair dye itself. When dyeing hair, the cuticles found in the outer layer of the hair must first be opened with ammonia in order for the hair colour to be able to penetrate into the cortex of the hair. After the cuticles are open, there’s usually a two-step process that happens simultaneously, removing the original pigments in the hair using peroxide and depositing in couplers, which are chemical compounds that define the colour of the hair dye. Lastly, conditioners are use to close off the hair cuticles to seal in and protect the new colour. (Helmenstine, 2013)

Hair Couplers
Hair Couplers

(Wikipedia, 2013)

Even though the first commercial and “safe” hair dye was produced in 1909 and over 75% of American women dye their hair, but to what extent is hair dye safe for us to use? Studies have shown that there’s a strong positive correlation between older hair dyes and cancer as the old compounds that made up the couplers were carcinogenic. However ever since they were identified, companies have altered the compounds for these couplers and they are no longer a problem anymore. But since then, new studies have also emerged showing that the new dyes may be indirectly causing cancer too. Researchers have found out that chemicals called secondary amines, which are found in all permanent hair dyes, are able to penetrate into our skin and hair, and remain there for up to years after the dyes are applied. Over time these secondary amines could react with tobacco smoke, exhaust fumes, or other substances to form a highly poisonous chemical known as N-nitrosamines. (Brown Girl, 2013)

Secondary Amines
Secondary Amines

(Wikipedia, 2013)


(Wikipedia, 2013)

At the same time, hair dye is known to irritate the skin and cause skin discolouration due to the fact that our skin is also made up of the same type of keratinized protein as hair. However, this discolouration typically disappears within a few days as the skin naturally renews itself. Hence, a good way to prevent the discolouration of the skin is to apply a thin layer of petroleum jelly and wear latex gloves to protect the hands. (Wikipedia, 2013)

In conclusion, although the old hair dye problems have been solved, new problems are still arising and shouldn’t be ignored. So to be on the safe side, one can use hair dye, but just use it with caution, and don’t apply it regularly as it allows the build up of these secondary amines.

– Helmenstine, A. M., & Ph.D.. (n.d.). Hair Color Chemistry – How Haircoloring Works. Chemistry – Chemistry Projects, Homework Help, Periodic Table. Retrieved September 1, 2013, from
– Hair coloring – Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the free encyclopedia. Retrieved September 1, 2013, from
– Amine – Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the free encyclopedia. Retrieved September 1, 2013, from
– Nitrosamine – Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the free encyclopedia. Retrieved September 1, 2013, from
– Column of Controversy: Hair Dye vs. Cancer | Brown Girl Magazine. (n.d.). Brown Girl Magazine | The Premier Magazine for Young South Asian Women. Retrieved September 1, 2013, from

Bubble Monster!

After a long day, before going to bed, we head into the bathroom, step into the shower and slather on shampoo, shower gel, and face wash. In the morning, before heading to school, we head to the bathroom where we follow the same routine. As we learned in biology, the epidermis is our largest organ, and perhaps in efforts to keep it clean, we’re actually creating a chemical imbalance between our skin’s natural pH, around 5.5 and a alkaline range around a pH of 8, which can lead to higher levels of bacteria on the skin (Health & Goodness, 2013). We use these products everyday without thinking twice about it, but they are made up of dozens of chemicals, chemicals with which we are not necessarily familiar. Do we know the effects these chemicals have on our skin and whether or not they are safe?

Woman washing face

Picture 1: Woman washing her face (Gruber, 2013)

The chemical makeup of soap and the convenience of bathing have drastically changed as technology has improved, yet human reverence for soap has remained the same. Traditionally, soap was made from the chemical reaction between an animal’s triglycerides and an alkali like sodium or potassium salt which, after a chemical reaction creates a mixture of soap, water, and glycerine (which attracts moisture and allows our skin to stay soft). Traditional soap worked with a skin’s natural pH to cleanse but not over-dry. However, with the advancement of modern science, the makeup of soap has changed. Modern day soap is made of chains of hydrocarbons (Duncan, 2009).

Soap molecule

Picture 2: Chain of hydrocarbon (nsb, 2013)

These chains attach to the oil or grease on the body at one end, and on the other end, attach themselves to water molecules, creating a lather which when rinsed, also rinse the dirt off our bodies as well (Duncan, 2009) in a process called saponification (HSC, 2013). Although this modern day soap can be considered more effective, especially in killing bacteria, it is also more abrasive, often cleansing the oils naturally produced by our skin to keep it soft.


Picture 3: Process of Saponification (HSC, 2013)

There has been a long-time debate over whether one can have too much of a good thing. When it comes to showering, the answer is “Yes!” The outermost layer of our skin, called the stratum corneum, is a barrier made of hardened dead skin cells and is held together by lipids, a kind of fatty compound that moisturizes the skin. The stratum corneum is a form of protection for the living and healthy cells underneath it. However, when we shower and cleanse our skin with these chemical astringents, the stratum corneum suffers damage through abrasion and over-drying, forcing the body to repair it. (Clark, 2009) If we shower too many times a day and our body can’t keep up with the pace that we are damaging our stratum corneum, our skin becomes dry, irritated, and cracked, something no one wants as it’s ugly, itchy, and painful (Silva, 2013).

Picture 4: Skin layers (Wikipedia, 2013)

Structural Formula of Lipids

Picture 5: Structural Formula of Lipids (Lipid Library, 2013)

It’s no wonder why we regard soap so highly and think it’s a cure-all. During the olden days, people didn’t shower as often since it was harder for them to acquire water and to heat it as well. They would have to walk miles to and from their house with a bucket to get water, which could take up to half a day. To lower the frequency of this inconvenience, they would only shower once in a while. On a recent trip to Tibet, I learnt from a Tibetan monk that some traditional local people only shower just 3 times in a lifecycle: once when they’re born, once when they get married, and once just after they pass away. This proves that showering daily is not a necessity. However, ever since 1889 when Edwin Ruud invented the in-home water heater (Clark, 2009)allowing hot water to be sent directly to the shower, people have been showering more and more often, sometimes even up to 5 times a day.

Although it is important for us to stay clean, it is still vital for us to strike a balance between clean and healthy skin. Showering only once a day is better for our skin’s health. It maintains a healthy skin pH of around 5.5 and it keeps the skin from becoming irritated and dry. Perhaps we shouldn’t be misled by the convenience of a shower in our home and modern soaps, which are too astringent-like in cleansing the skin, to believe that being ultra clean is the healthy choice. In many ways before all these modern advancements, people actually had healthier skin.


  • Duncan, Aida.  “Face Soap 101”  20 August 2009. <>  28 January 2013.
  • Clark, Josh.  “Is a daily shower too much for your skin?”  03 September 2009. <>  28 January 2013.
  • Ganzel, B. (n.d.). Indoor Plumbing Arrives in Rural America during the 1930s. Wessels Living History Farm, Inc.. Retrieved January 29, 2013, from
  • Silva, R. (n.d.). Learn How to Shower To Keep Your Skin Healthy. Health Guidance – Free Health Articles. Retrieved January 29, 2013, from
  • Health & Goodness. (n.d.). Skin pH And Skin Health. Health & Goodness – Information, inspiration and healthy living products.. Retrieved February 5, 2013, from
  • HSC. (n.d.). HSC Online – Industrial Chemistry: 5. Saponification. NSW HSC Online. Retrieved February 5, 2013, from


  • The Importance of Washing Your Face | The Luxury Spot. (n.d.). Bryce Gruber – Official Blog of Bryce Gruber – The Luxury Spot. Retrieved January 29, 2013, from
  • Cleaning Aciton of Soap by Structure – Nsb Notes. (n.d.). Nsb Notes. Retrieved January 29, 2013, from
  • File:Skinlayers.png – Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the free encyclopedia. Retrieved January 29, 2013, from
  • Lipid Library. (n.d.). Waxes, structure, composition, occurrence and analysis. . Lipid Library – Lipid Chemistry, Biology, Technology and Analysis. Retrieved February 5, 2013, from