History and Science of Soaps and Cleansers

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Questions and Answers

Which statement accurately describes the advantages of synthetic soaps compared to regular soap?

They are always less effective at removing dirt.

They contain no preservatives.

They are more alkaline than regular soap.

They usually cause less skin irritation. (correct)

Why is lather not always desirable in certain cleaning applications?

It indicates the presence of antibacterial agents.

It can leave residues that are difficult to rinse away. (correct)

It enhances the cleaning performance.

It helps to moisturize the skin.

What can be adjusted in synthetic soaps to match normal skin pH?

Temperature of the water used.

Acidity levels by adding citric acid or lactic acid. (correct)

Coloring agents introduced.

The scent of the soap.

What function does lather serve in the context of cleaning products?

It indicates that detergent activity remains. Signup and view all the answers

Which of the following is NOT typically an ingredient found in soaps and cleansers?

Heavy metals Signup and view all the answers

What was the primary reason for the decline in bathing after the fall of Rome?

Poor sanitation and hygiene-related diseases Signup and view all the answers

Which historical figure is associated with the introduction of hand sanitizers in infection control?

Unknown; concerns arose in the mid-1800s Signup and view all the answers

What is the origin of the name 'soap' according to ancient Roman legend?

From the ashes of burnt animal fat on Mount Sapo Signup and view all the answers

What practice did the Greeks use to maintain cleanliness prior to soap production?

Scraping off oil and dirt with a strigil Signup and view all the answers

What major societal change occurred in the 17th century regarding personal cleanliness?

Personal cleanliness became popular again after a decline Signup and view all the answers

What was the main reason cited for the rejection of the 2004 study linking parabens to breast cancer?

It had several significant limitations. Signup and view all the answers

Which of the following conclusions did CIR make regarding parabens in 2006?

There was no need to change its original conclusion from 1984. Signup and view all the answers

What concentration levels of methylparaben and ethylparaben were deemed safe by SCCS in 2011?

0.4% if used alone or 0.8% in combination. Signup and view all the answers

What was the Danish government's action regarding parabens for children under 3 years old?

They banned the use of propyl and butylparaben. Signup and view all the answers

What is the main reason given for the widespread claims about parabens causing breast cancer despite the lack of confirming studies?

Issues of endocrine disruption have been reported. Signup and view all the answers

According to studies, how does the potency of butyl paraben compare to naturally produced estrogen?

It is 10,000-100,000 times less potent than naturally produced estrogen. Signup and view all the answers

What has not been clearly demonstrated about triclosan?

Its clinical benefit for patients. Signup and view all the answers

What was one of the main outcomes of the SCCS's re-evaluation of parabens after Denmark's ban?

A ban on parabens in certain cosmetics for infants. Signup and view all the answers

What primary property distinguishes surfactants used in cosmetic formulations?

Their detergency and emulsification properties Signup and view all the answers

Why is it essential for the hydrophilic and hydrophobic parts of a surfactant molecule to be of comparable strength?

To ensure effective surfactant properties Signup and view all the answers

Which type of surfactant is made from sodium salts of fatty acids?

Anionic surfactants Signup and view all the answers

What is the role of warm water in the emulsification process of grease?

To melt the grease and facilitate droplet formation Signup and view all the answers

What is the first step of the cleansing action of a detergent?

Wetting Signup and view all the answers

Which property is NOT essential for effective detergency?

Ability to impart fragrance Signup and view all the answers

What is an example of a condition that assists in the emulsification of grease?

Agitating the mixture Signup and view all the answers

What type of surfactant is characterized as a surface-active agent without a charge?

Non-ionic surfactants Signup and view all the answers

What evidence is presented regarding the effectiveness of triclosan compared to non-antibacterial hand soaps?

Triclosan shows no added benefit over non-antibacterial soaps. Signup and view all the answers

What potential harm is associated with the use of triclosan?

It may contribute to antimicrobial resistance. Signup and view all the answers

What possible effects does sodium lauryl sulfate (SLS) have on the skin?

It can cause dermatitis and skin irritation. Signup and view all the answers

What does the FDA currently do regarding triclosan?

It is actively reviewing its safety and efficacy. Signup and view all the answers

What significant findings were reported from studies involving SLS on animal skin?

SLS caused severe epidermal changes in application areas. Signup and view all the answers

Which of the following best describes the potential comedogenic effects of SLS?

SLS can produce significant numbers of comedones. Signup and view all the answers

What type of skin condition can SLS potentially trigger in some users?

Dermatitis and irritation. Signup and view all the answers

What has been concluded about the carcinogenicity of SLS in studies on animals?

SLS has not been shown to be carcinogenic. Signup and view all the answers

What is the maximum concentration of Sodium Laureth Sulfate (SLES) that should be found in leave-on products?

1% Signup and view all the answers

What concerns are associated with microbeads used in scrubs?

They can contribute to environmental pollution. Signup and view all the answers

How does Sodium Laureth Sulfate (SLS) affect skin safety?

Appears safe for short periods with rinsing. Signup and view all the answers

Which of the following ingredients is used in cosmetic formulations to improve texture and spreadability?

Cyclopentasiloxane Signup and view all the answers

Which of the following statements about the environmental impact of microbeads is true?

They can enter water bodies after wastewater treatment. Signup and view all the answers

What type of ingredients are categorized as microbeads?

Natural or synthetic tiny particles. Signup and view all the answers

What is the role of the ingredient Disodium EDTA in cosmetic formulations?

Helps to chelate metal ions. Signup and view all the answers

Which of the following statements about the use of SLS is true?

It may cause irritation if left on the skin. Signup and view all the answers

What type of ingredient is Sodium Lauroyl Sarcosinate?

A surfactant. Signup and view all the answers

Which of the following is NOT a concern when using microbeads?

Increased exfoliation effectiveness. Signup and view all the answers

Study Notes

Skin Cleansing

October 15 is Global Handwashing Day
Handwashing with soap and water is recommended.

History of Skin Cleansing

Salt was used for cleansing by Chinese, Egyptians, and Greeks.
Soap manufacturing began in ancient Babylon around 2800 BC. Methods involved boiling fats with ashes and water.
Greeks used strigils to scrape off oil and dirt.
Clay and sand were also used.
Romans lived in water-rich areas. They built aqueducts to bring clean water, which made bathing popular.
An ancient Roman legend traces soap origins to Mount Sapo (Rome), where sacrificed animal fats and wood ash mixed in the Tiber river created a cleansing clay mixture.
Bathing declined and sanitation worsened after the fall of Rome. This led to hygiene-related diseases like the Black Death (14th century).
Deaths of 75 to 200 million people in Europe occurred during the 1347-1351 Plague.
Personal cleaning became popular again in the 17th century.

Ancient Soap Making

Medieval soaps in Northern Europe were made with wood ashes and animal/fish oils.
Resultant soaps were unpleasant smelling soft soaps.
Soap was used in textile/clothing cleaning.
Use for personal washing was not common in early times.
Syria was known for its pleasant hard soaps.

Hand Sanitizers

Hand sanitizers are adjuncts, not replacements for soap and water, according to the CDC.
Concerns about the use of hand sanitizer as part of infection control first arose in the mid-1800s.
The Hungarian obstetrician Ignaz Semmelweis, a pioneer in antiseptic hygiene in mid-1800s, advocated for hand washing in a chlorine solution before examining women to reduce the spread of disease. This action effectively reduced infections.

Skin Cleansers

Skin cleansers remove dirt, makeup, environmental pollutants, germs, and other soilings from the skin.
Examples of cleansers include facial cleansers, bath and shower products, hand cleansing products, including hand sanitizers.

Dirt Removal

Skin is soiled with solid particles stuck to the sebum (oil).
These substances include skin scales, dust, soot, salt, urea, bacteria, and cosmetics/makeup residue.
Other substances carried in the air are also deposited on the skin.

Grease Removal from Skin

Removing grease from skin involves three methods:
Emulsification using surfactants (e.g., shower gels, shampoos).
Dissolving excess oils with more oils (e.g., creams, body oils).
Absorbing the oils using absorbent materials (e.g., cleansing masks, kaolin).

Soap as a Cleanser

Soaps are made from reacting animal and vegetable fats/oils with alkalis.
Hard soaps are sodium salts of fatty acids from animal/vegetable sources (e.g., sodium stearate).
Soft soaps (liquid soaps) are potassium salts of fatty acids.
Soap names came from Roman Legend.

Synthesis of Soap

A chemical reaction between glycerol tristearate (fat) and sodium hydroxide (alkali) produces sodium stearate (soap) and glycerol.

How Soap Works

Soap particles coat fat droplets that hold dirt.
The soap particles and the dirt are washed away with water.

Disadvantages of Regular Soap

In hard water, regular soap forms an insoluble scum (calcium and magnesium salts).
This scum may stick to the skin, causing irritation.
Regular soaps are typically salts of weak acids and strong alkalis, which results in a high pH (9-10). This may irritate skin (normal skin pH, 4-6.5).

Surfactants as Cleansers

Water is not effective for cleaning greasy surfaces as it's repelled by oil.
Surfactants are molecules with both water-loving (hydrophilic) and oil-loving (hydrophobic) parts.
Surfactants are used in many cosmetic and toiletry products (e.g., detergents, foaming, conditioning, solubilization, emulsification).
Selecting surfactant for use must consider the functions they need to fulfill in a cosmetic product (e.g., detergency, emulsification, foam quality).

Synthetic Soaps (Soapless Soap)

Synthetic soaps are made from surfactants.
Four types of surfactants: anionic, cationic, non-ionic, amphoteric.
Sodium salts of fatty acids are anionic.

Detergent

A detergent is an agent that removes dirt.
Several types of detergents exist (mild, strong, ionic, non-ionic), depending on the type of dirt and surface.
Three essential properties of detergents:
- Wet the surface
- Displace dirt from the surface
- Solubilize the dirt in solution.

Cleansing Action of a Detergent

Wetting: The detergent reduces the surface tension of water, allowing it to spread across a greasy surface.
Emulsification: The detergent molecules bind to the grease, forming droplets dispersed in the water.
Rinsing: Water removes the emulsified grease and loosened dirt.

Surfactant Classes

Anionic (sulfates, phosphates, carboxylates)
Cationic (quaternary ammonium salts)
Zwitterionic/Amphoteric (amino propionates, glycinates)
Nonionic (ethoxylates)

Anionic Surfactants

Sodium lauryl sulfate (SLS)
- A detergent
Sodium C12-15 pareth-15-sulfonate
A detergent

Cationic Surfactants

Hexadecyl(cetyl) trimethyl ammonium bromide

Amphoteric Surfactant

Cocoamphoglycinate

Betaines

Coco-betaine and N-coco-N-dimethyl glycine are examples.
Used in baby shampoos and other products to improve lather and viscosity.

Nonionic Surfactants

Sorbitan esters (Tweens, Spans).
No incompatibility problems with other ingredients.

Functions of Surfactants

Detergency, foaming, conditioning, solubilization, emulsification.

Advantages of Synthetic Soaps

Usually cause less skin irritation than traditional soap.
The pH can be adjusted to normal skin using citric acid or lactic acid.

Lather and Foam

Lather plays little or no role in the cleansing action of soap/detergents.
It is helpful in some applications such as automatic washing machines, but special products("low lather") are available.
Lather is an indicator of cleanser activity, and it holds the cleanser on the surface for rinsing.

Ingredients in Soaps and Cleansers

Moisturizers: help counteract dryness caused by soap. Examples include glycerin, lanolin, and vegetable fats.
Preservatives
Coloring agents
Fragrances
Antibacterial substances
pH altering substances (e.g., citric acid)
Other ingredients

Transparent Soap

Contains high glycerin concentrations for transparency and mildness.

Antibacterial Substances

Antibacterial soaps often contain substances like triclosan.
Some remain after washing and inhibit bacteria growth.
Used to prevent body odor, acne, or hair follicle infections and following exposure to dirt or contamination.

Other Ingredients

Other natural ingredients/Additives (Vitamins, Herbs etc) may exist but have no documented medical value.
Soaps are in contact with the skin briefly so these additives are quickly washed off.

Mild/Hypoallergenic Soap

Often used for people with sensitive skin and infants.
Typically have no fragrances, coloring agents.
Often contain surfactants from the betaine group that are known for their mildness and lack of stinging.

Soaps vs. Soapless Cleansers

Different behavior in hard water: Soap forms scum; Soapless detergents do not.
pH of soapless cleansers can be adjusted to normal skin, lowering irritation.

Lotions and Liquid Preparations for Facial Cleansing

Oil-in-water emulsions: oils dispersed in water.
- Easier to remove from the skin.
Fresh-up pads/tissues: Tissues saturated with cleansing lotion to remove makeup.

Advantages of Creams/Liquids for Facial Cleansing

Easy makeup removal
Suitable for dry skin (oil content).
Can be used further away from bathroom.

Cleansing Creams

Designed for makeup removal, not moisturizers.
Should be rinsed off immediately to avoid surfactant-based irritation.
Better washed with water than wiped to remove.

Abrasive Cleansers (Scrubs)

Creams/emulsions with tiny granules for physical skin cleaning.
Gentle use is recommended for normal skin. Frequent use can damage sensitive skin.

Solutions of Surfactant in Water

No oil phase soapless cleanser.
Suitable for oily skin.
Typical ingredients: surfactant, water, perfume (color, preservative).

Ingredients Causing Safety Concerns: Parabens

Mixtures of parabens may reduce individual levels while increasing effectiveness.
Studies in the 21st century show low potential risk of breast cancer and endocrine disruption.
Regulations restrict paraben level in products.

Ingredients Causing Safety Concerns: Triclosan

Used in antibacterial personal care products.
Effectiveness in reducing bacterial counts on hands may be questioned.
Shown to be unnecessary and may contribute to antibiotic resistance and have potential hormonal effects.
Is under review by the FDA.

Ingredients Causing Safety Concerns: SLS

Irritative ingredient that causes skin and mucous membrane irritation.
Not carcinogenic but can cause skin irritation, in some cases.
May be safe when used in short periods with rinsing..
May not be suitable for leave-on applications.

Ingredients Causing Safety Concerns: Microbeads

Tiny particles used in scrubs, made from natural materials or plastics.
Can be a health concern due to their potential impact on wastewater systems.

Ingredients Including Specific Chemical Examples

Specific chemical examples and their related uses/properties are noted where available in the provided text.

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Description

Explore the intriguing history and scientific principles behind soap and cleansers in this quiz. From ancient practices to modern formulations, test your knowledge on the advantages of synthetic soaps, historical figures involved in hygiene advancements, and the role of lather in cleaning applications.