HOMOSALATE

DESCRIPTION
Homosalate is a chemical compound commonly used in sunscreens and other skincare products for its UV-filtering properties. 
Homosalate is an ester of salicylic acid and homomethyl salicylate, and its primary role is to absorb UVB radiation, helping to protect the skin from sunburn and damage caused by ultraviolet light. 
Homosalate is considered to be a relatively mild sunscreen agent and is often used in combination with other UV filters to provide broad-spectrum sun protection.
 
Cas Number
118-56-9
 
SYNONYMS
Homosalicylate,2-Ethylhexyl Salicylate,Ethylhexyl Salicylate
 

Sunscreens are a critical component in protecting the skin from harmful ultraviolet (UV) radiation, which is responsible for various skin conditions, including sunburn, premature aging, and an increased risk of skin cancer. 
The primary active ingredients in sunscreens are typically classified into two categories: physical (mineral) sunscreens and chemical sunscreens. 
Chemical sunscreens contain organic compounds that absorb UV radiation and convert it into harmless heat, whereas physical sunscreens, such as those containing zinc oxide or titanium dioxide, act as barriers by reflecting UV rays.
 
One of the common ingredients used in chemical sunscreens is Homosalate. 
Homosalate is an organic UV filter that specifically absorbs UVB rays, providing protection against sunburn and skin damage. 
Despite being widely used in sunscreens and cosmetic products, homosalate is not as well-known to the general public as other sunscreen agents, such as avobenzone or oxybenzone. 
However, it plays a crucial role in the formulation of sunscreen products by enhancing their effectiveness and broadening the range of UV protection.
 
This article provides an in-depth scientific exploration of homosalate, covering its chemical structure, mechanism of action, regulatory status, safety, environmental impact, and more. 
By the end of this review, readers will gain a comprehensive understanding of homosalate's role in sunscreens and its significance in the context of dermatology, public health, and safety.
 
Chemical Structure and Properties
Homosalate, scientifically known as 2-Ethylhexyl Salicylate, is an organic ester of salicylic acid and 2-ethylhexanol. 
The chemical formula of homosalate is C18H26O3, and it has a molecular weight of approximately 290.4 g/mol. 
The ester bond between salicylic acid and 2-ethylhexanol is key to its function as a UV-absorbing agent.
 
Molecular Structure
The molecular structure of homosalate features a benzene ring, which is part of the salicylate group, attached to a long hydrocarbon chain derived from 2-ethylhexanol. 
This structure enables homosalate to absorb UVB radiation effectively. 
The presence of the benzene ring contributes to the compound's ability to absorb light in the UVB spectrum (290–320 nm).
 
Physical Properties
Appearance: Homosalate is a colorless to pale yellow liquid at room temperature.
Solubility: It is lipophilic (fat-soluble) and has low water solubility. 
This property allows it to mix well with other oil-based ingredients in sunscreen formulations.
Boiling Point: Approximately 295°C.
Melting Point: Homosalate does not have a defined melting point but remains liquid at typical room temperatures.
Stability: The compound is generally stable under normal conditions but can degrade when exposed to prolonged sunlight, high temperatures, or air. 

Stabilizers are often added to sunscreen formulations to prolong homosalate's efficacy.
Functionality in Sunscreen Formulations
Due to its solubility in oils and lipids, homosalate is often incorporated into non-water-based sunscreen formulations. 
Its stability is also enhanced in formulations containing other UV filters, antioxidants, and emulsifiers, ensuring long-lasting protection during sun exposure.
 
History and Development
Homosalate has been utilized in sunscreen formulations since the 1970s, with increasing demand for chemical sunscreens driven by the rising awareness of UV-induced skin damage. The development of sunscreen ingredients has evolved alongside advancements in our understanding of the harmful effects of UV radiation and the growing popularity of sun protection in daily skincare routines.
 
Historical Context
The use of chemical filters in sunscreens dates back to the early 20th century. 
However, the need for more effective and broad-spectrum protection led to the discovery and introduction of various organic UV filters, including homosalate. 
Homosalate was introduced as a safe and effective UVB filter, often used in combination with other agents like avobenzone, oxybenzone, and octinoxate.
 
Scientific Evolution
Early formulations focused primarily on protecting against UVB radiation, which is responsible for causing sunburn. 
As research progressed, it became clear that UVA radiation, which penetrates deeper into the skin, also contributes to aging and cancer risks. 
As a result, sunscreen formulas evolved to include both UVB and UVA filters, leading to the development of broad-spectrum sunscreens.
 
Today, homosalate continues to be used in combination with other organic and inorganic UV filters to provide comprehensive protection from both UVB and UVA rays. 
The ability to tailor sunscreen formulations to specific needs—whether for water resistance, high SPF, or gentle formulations for sensitive skin—has made homosalate a popular ingredient.
 

Mechanism of Action
Homosalate functions as an UVB filter, absorbing ultraviolet radiation in the UVB spectrum (290–320 nm). UVB rays are the primary cause of sunburn, DNA damage, and increased skin cancer risk. 
By absorbing UVB radiation, homosalate prevents these rays from penetrating the skin and causing damage.
 
UV Absorption
Homosalate absorbs UVB rays through its aromatic ring structure, which enables the molecule to undergo an electronic transition when exposed to UV light. 
The energy absorbed is converted into heat, which is dissipated harmlessly into the surrounding skin layers. 
This process prevents UV radiation from reaching deeper skin layers where it could cause DNA damage, leading to conditions such as sunburn and skin cancer.
 
Comparison with Other Sunscreen Agents
While homosalate is effective at filtering UVB rays, its broad-spectrum protection is limited compared to other ingredients like avobenzone, which absorbs UVA radiation as well. 
As a result, homosalate is often used in combination with other sunscreen agents to create a more complete sunscreen product. 
Some sunscreens contain a combination of homosalate with agents such as octinoxate or octocrylene, which also absorb UVB radiation.
 
Homosalate's absorption profile is not as broad as some other filters, but it provides effective protection against sunburn, which is why it is commonly included in formulations that target sunburn prevention specifically.

SAFETY INFORMATION ABOUT HOMOSALATE
 
 
 
 
First aid measures:
Description of first aid measures:
General advice:
Consult a physician. 
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
 
If inhaled:
If breathed in, move person into fresh air. 
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately. 
Wash off with soap and plenty of water.
Consult a physician.
 
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
 
If swallowed:
Do NOT induce vomiting. 
Never give anything by mouth to an unconscious person. 
Rinse mouth with water. 
Consult a physician.
 
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
 
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment. 
 
Avoid breathing vapours, mist or gas. 
Evacuate personnel to safe areas.
 
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste. 
Keep in suitable, closed containers for disposal.
 
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
 
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place. 
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
 
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
 
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles. 
Faceshield (8-inch minimum). 
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
 
Skin protection:
Handle with gloves. 
Gloves must be inspected prior to use. 
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product. 
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. 
Wash and dry hands.
 
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
 
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. 
 
If the respirator is the sole means of protection, use a full-face supplied air respirator. 
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so. 
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions. 
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
 
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company. 
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product