CYCLOPENTASILOXANE
CYCLOPENTASILOXANE
In beauty products, cyclopentasiloxane is mainly used as a conditioner, delivery agent, lubricant and solvent.
Like all other silicones, cyclopentasiloxane has a unique fluidity that makes it easily spreadable.
When applied to the skin and hair, cyclopentasiloxane gives a silky and slippery feeling to the touch and acts a mild water repellent by forming a protective barrier on the skin.
Cyclopentasiloxane can also fill in fine lines and wrinkles, giving the face a temporary “plump” look.
Cyclopentasiloxane is a common ingredient in skincare and body care products, used to improve the texture of formulations, helping products to glide on smoothly and evenly. It also has the added benefit of acting as a protective barrier to the skin, protecting the skin from moisture loss, allergens, and bacteria.
Cyclopentasiloxane is part of a family of small silicones called cyclomethicones. Cyclomethicones are clear, odorless liquids utilized in skincare products to give your skincare a smooth texture that allows the product’s key ingredients to be delivered evenly to the skin. Cyclomethicones are part of the silicone family and are used in a similar way to dimethicone, which you may be familiar with. Cyclomethicones help smooth the texture of products, improve the appearance of scarring, increase the water-resistance abilities of formulations, and emulsify the product. However, cyclomethicones are also better at delivering active ingredients to the skin as they are more volatile than larger silicones and slowly evaporate from the skin. When cyclomethicones disappear, they leave behind the formulation’s essential ingredients.
Cyclopentasiloxane is one of the most common ingredients used in personal care products today. Synthetically manufactured, it is a silicone derivative that carries a variety of skin and hair applications, such as hair spray and sunscreens. With a broader focus on uses in styling, cyclopentasiloxane is finding more and more popularity in hair care products, and those where a microscopic protective layer may benefit the skin.
Cyclomethicones are sometimes also called cyclosiloxanes; they are different names for the same class of chemicals. The two most commonly used cyclomethicones are cyclopentasiloxane and cyclohexasiloxane; you may have seen these ingredients somewhere near the bottom of your product’s ingredients list.
Cyclopentasiloxane has a ring-shaped structure that makes it more volatile or less stable. This instability allows cyclopentasiloxane to evaporate when applied to your skin—making it an excellent ingredient for products that need to go on smoothly but not remain sticky after application. As all the cyclopentasiloxane eventually evaporates from the surface of the skin, it leaves behind the other key components in the product to work their magic. This action of evaporation makes it an excellent carrier ingredient.
Cyclopentasiloxane is a clear, odorless, silicone-based oil that is incredibly useful and versatile in bath & body recipes. This is a direct replacement for Cyclomethicone
Perfect as a carrier, it can provide a silky and soft feel to your products, and can improve spreading qualities of fragrance as well.
Perfect for Antiperspirants, deodorants, hair care, skin care and perfumes.
Cyclopentasiloxane (D5) (CAS n. 541-02-6, EC 208-764-9) is widely used in cosmetic products due to its unique functions as antistatic, emollient, humectant, solvent, viscosity controlling and hair conditioning agent
Cyclopentasiloxane (D5)
AEC Cyclopentasiloxane; Botanisil CP-33; Dow Corning 245 Fluid; KF995; Mirasil CM 5; SF 1202; Wacker-Belsil CM 040; Execol D5
CAS: 541-02-6
EC: 208-764-9
Cyclopentasiloxane is a volatile polydimethylcyclosiloxane composed mainly of cyclopentasiloxane.
The product is clear, tasteless, essentially odorless, non-greasy and non-stinging.
Cyclopentasiloxane may be used alone or blended with other cosmetic fluids to provide a fluid base for a variety of cosmetic ingredients.
It features good solubility in most anhydrous alcohols and in many cosmetic solvents.
Cyclopentasiloxane is a volatile fluid with appreciable vapor pressure at ambient temperature.
Unlike other volatile carriers used in the personal care industry, volatile silicone fluids do not cool the skin when they evaporate.
This is a consequence of their unusually low heat of vaporization.
Cyclopentasiloxane (its full chemical name is decamethylcyclopentasiloxane), commonly known as D5, is a chemical that belong to the group of cyclomethicones aka methyl siloxanes.
Siloxanes are found in lots of hair care and skin care products as conditioners that leaves hair and skin with a soft, silky, and moist feeling.
You can identify siloxanes in cosmetics by looking for the words with “-siloxane” or “-methicone” in the ingredient list.
Cyclopentasiloxane (D5) is an odorless, colorless liquid. It is also used in the production of silicone polymers and may also be used as a dry-cleaning solvent and in industrial cleaning products.
Cyclopentasiloxane (D5) is rated 3 out 10 (10 being most toxic) in the Skin Deep database powered by the Environmental Working Group (EWG).
Cyclopentasiloxane is a silicone compound with the formula [(CH3)2SiO]5.
Cyclopentasiloxane is a colorless, odorless liquid that has a low viscosity.
Cyclopentasiloxane gives a silky and slippery feel when applied to skin and hair.
Cyclopentasiloxane is mainly used in antiperspirants, sun-block creams, hair conditioners and skin care products.
CYCLOPENTASILOXANE is classified as :
Emollient
Hair conditioning
Skin conditioning
Solvent
CAS Number: 541-02-6
EINECS/ELINCS No: 208-764-9
Chem/IUPAC Name: Decamethylcyclopentasiloxane
CYCLOPENTASILOXANE
INCI: Cyclopentasiloxane
What is Cyclopentasiloxane?
Cyclopentasiloxane, also known as CSP, is synthetic compound, in cyclic siloxane group. Cyclopentasiloxane in normal terms is a silicone. Cyclic siloxanes are mainly colorless, odorless liquid with low viscosity. It is a low-cost option for vegetable oil or any other animal source. It also acts as a volatile solvent.
Use & Benefits:
Siloxanes are preferred over other volatile alternatives because it does not leave the skin dry. Cyclopentasiloxane forms a thin film over skin or hair.
This film is non-greasy, but at the same time, water repellent does not let moisture evaporate and provide the emollient effect.
Cyclopentasiloxane also spreads more evenly and faster even when rubbed over the skin or hair surface. Cyclopentasiloxane also helps improves hair appearance, shine, and manageability. Because of the film, the environmental effect on skin /hair can be avoided, in other words, it also produces a protective film over skin and hair. It is used in skin products, sunscreens, color cosmetics, hair care, lotions, facial make-up, and rinse-off products.
Although it creates a film over the hair, this film is not always desirable like many silicons as it can make the hair feel greasy and may if even take a cleansing shampoo that strips the hair of oils to get rid of the film feel to the hair (this is usually the case for curlier hair types). This is however determined by how much of the silicon is added to the product. If in the formula it is close to the top of the ingredients, then this will indicate that there is a high percentage and so most likely give that film feel.
The purpose of silicons in hair conditions or shampoos is for manageability and ease of combing.
The EU in 2018 put a restriction on the use of Cyclopentasiloxane to 0.1% in wash-off products as use above this was reported to accumulate in the water supply.
Prior to this, there was already controversy on the environmental and potential health risk Cyclopentasiloxane could cause.
EWG has classified this ingredient as safe to use in its intended concentration. It has also not been recognized as an endocrine disruptor. It is used in skin products, sunscreens, color cosmetics, hair care, lotions, facial make-up, and rinse-off products.
The purpose of silicons in hair conditions or shampoos is for manageability and ease of combing
INCI: Cyclopentasiloxane
Cyclopentasiloxane is a clear, odorless, silicone-based oil that is incredibly useful and versatile in bath & body recipes. This is a direct replacement for Cyclomethicone
Perfect as a carrier, it can provide a silky and soft feel to your products, and can improve spreading qualities of fragrance as well.
Perfect for Antiperspirants, deodorants, hair care, skin care and perfumes.
INCI NAME: Cyclopentasiloxane
Features &
Benefits
• Volatile carrier
• Compatible with a wide range of cosmetic ingredients
• Low surface tension
• Imparts soft silky feel to the skin
• Excellent spreading
• Leaves no oily residue or build up
• Detackification
• Non-greasy
Applications
• A base fluid in a number of personal care products, with excellent spreading, easy rubout and lubrication properties together with unique volatility characteristics.
• Antiperspirants, deodorants, hair sprays, cleansing creams, skin creams, lotions and stick products, bath oils, suntan and shaving products, make-up, nail polishes.
• In sticks, it has the right balance between volatility and spreading.
Cyclopentasiloxane
INCI NAME: Cyclopentasiloxane
FEATURES
• Volatile carrier
• Compatible with a wide range of cosmetic ingredients
• Low surface tension
BENEFITS
• Imparts soft silky feel to the skin
• Excellent spreading
• Leaves no oily residue or build up
• Detackification
• Non-greasy
APPLICATIONS
Cyclopentasiloxane is a base fluid in a number of personal care products, with excellent spreading, easy rub-out and lubrication properties together with unique volatility characteristics.
Cyclopentasiloxane is used in antiperspirants, deodorants, hair sprays, cleansing creams, skin creams, lotions and stick products, bath oils, suntan and shaving products, make-up, nail polishes.
Cyclopentasiloxane is used in sticks, it has the right balance between volatility and spreading.
TYPICAL PROPERTIES
Specification Writers: These values are not intended for use in preparing specifications.
Please contact your ATAMAN CHEMICALS sales representative prior to writing specifications on this product.
Appearance: Colorless liquid
Specific gravity at 25°C (77°F): 0.95
Viscosity at 25°C (77°F) mm2.s-1: 4.0
Refractive index at 25°C (77°F): 1.397
Surface tension at 25°C (77°F): mN/m 18.0
Flash point – closed cup °C (°F): 77 (171)
Freeze point °C (°F) °C (°F): <-50 (<-58)
Boiling point at 760mm Hg: 205 (401)
Water content ppm: 250
Cyclotetrasiloxane (D4) content % <1.0
DESCRIPTION
Cyclopentasiloxane is a volatile polydimethylcyclosiloxane composed mainly of cyclopentasiloxane.
The product is clear, tasteless,essentially odorless, nongreasy and non-stinging.
Cyclopentasiloxane (D5)
HOW TO USE
Cyclopentasiloxane may be used alone or blended with other cosmetic fluids to provide a fluid base for a variety of cosmetic ingredients.
It features good solubility in most anhydrous alcohols and in many cosmetic solvents.
Cyclopentasiloxane is a volatile fluid with appreciable vapor pressure at ambient temperature.
Texture
Cyclopentasiloxane helps to produce a smooth, silky formulation that allows the product to spread evenly over the skin. It prevents the product from catching on dry skin patches and evens skin tone by gliding over pores and wrinkles. It ensures that all areas of the skin are receiving the key ingredients in your product.
Lightweight
Cyclopentasiloxane is a volatile substance – like all cyclomethicones. This allows it to gradually evaporate from the skin, leaving behind the product’s key ingredients without the heaviness of other silicone-based ingredients.
Inexpensive
One of the most significant benefits of cyclopentasiloxane is that it is an inexpensive ingredient for formulators. For example, cyclopentasiloxane may be used as a cheap alternative to organic ingredients like vegetable glycerin, and its concentrations in skincare items can be more easily varied because it is synthetically manufactured. Synthetic ingredients often have a bad reputation in the skincare world as they are considered not natural. This is a bit of a misunderstanding; artificial ingredients are usually safer than their plant or animal-derived counterparts as they contain fewer impurities. They are also better for the environment as they don’t need to be sourced from a natural resource.
Hydration
A study published in Skin Pharmacology and Physiology investigated cyclopentasiloxane effect on the skin. The study considered the occlusive nature of the cyclomethicones in general. Occlusive substances work by creating a physical barrier between the skin and the air, keeping moisture in and allergens and bacteria out.
The study found cyclomethicones to be non-occlusive due to the volatile nature of the ingredients. The volatility of the ingredient allows cyclomethicones to evaporate from the skin, only forming a protective barrier for a short period. These results are excellent news for congestive skin types as it prevents sweat and skincare ingredients being pushed deeper into the pores. However, occlusive barriers are generally useful for drier skin types as they prevent moisture loss. Cyclomethicones may still be beneficial for improving the appearance of dry skin as the rate at which the evaporation occurs provides the skin is slow, and the ingredients will still offer the skin with the protective barrier for some of the time it is on the skin.
Scarring
Cyclomethicones have been suggested to improve the appearance of scars with used in conjunction with other silicone ingredients. A study published in the Journal of Cutaneous and Aesthetic Surgery determined that silicone gel preparation significantly enhances the appearance of superficial, hypertrophic, and keloid scars. While this research has not been conducted into cyclomethicones specifically, it is related to the broader subgroup of silicones. Many of the silicone gel preparations contain cyclopentasiloxane or cyclohexasiloxane, which is used at the volatile element to deliver the other silicone ingredients to the skin.
Who Should Use Cyclopentasiloxane?
Cyclomethicone products are suitable for most skin types, including congested, dry, or sensitive skin types, as well as skin types that may have damaged skin barrier integrity.
Cyclopentasiloxane is a silicone regularly used in cosmetic products. It’s commonly found in medical implants, sealants, lubricants, and windshield coatings.
D5 is colorless, odorless, non-greasy, and water-thin. It doesn’t get absorbed into the skin. Rather, it evaporates quickly away from it. This property makes it a useful ingredient in cosmetic products that need to dry quickly, like antiperspirants and hair sprays.
It also has lubricating properties. This gives a slippery and silky feeling when applied to the skin and hair and allows the product to spread more easily.
DECAMETHYLCYCLOPENTASILOXANE
541-02-6
Cyclopentasiloxane, decamethyl-
Cyclomethicone 5
CYCLOMETHICONE
Dimethylsiloxane pentamer
2,2,4,4,6,6,8,8,10,10-Decamethyl-1,3,5,7,9,2,4,6,8,10-pentaoxapentasilecane
Dow corning 345 fluid
NUC silicone VS 7158
Cyclic dimethylsiloxane pentamer
Dekamethylcyklopentasiloxan
UNII-0THT5PCI0R
Ddecamethylcyclopentasiloxane
Union carbide 7158 silicone fluid
KF 995
VS 7158
0THT5PCI0R
Decamethylcyclopentasiloxane, 97%
MFCD00046966
Dow corning 345
Silicon SF 1202
Cyclopentasiloxane, 2,2,4,4,6,6,8,8,10,10-decamethyl-
CCRIS 1328
HSDB 5683
Dekamethylcyklopentasiloxan [Czech]
EINECS 208-764-9
decamethyl cyclopentasiloxane
SF 1202
BRN 1800166
Ciclopentasiloxane
Cyclomethicone D5
D5 Cyclomethicone
dimethylcyclopentasiloxane
Decamethylcylopentasiloxane
DSSTox_CID_7184
ACMC-209ld1
EC 208-764-9
DSSTox_RID_78338
DSSTox_GSID_27184
SCHEMBL28497
4-04-00-04128 (Beilstein Handbook Reference)
KSC493E2H
CHEMBL1885178
DTXSID1027184
CTK3J3223
BCP15826
Tox21_303170
ANW-31955
CD3770
AKOS008901199
ZINC169743678
DB11244
MCULE-6274880347
2,2,4,4,6,6,8,8,10,10-decamethyl-1,3,5,7,9,2,4,6,8,10-pentoxapentasilecane
KS-00000X48
NCGC00163981-01
NCGC00257224-01
AK608817
AS-59731
CAS-541-02-6
SC-81690
D1890
D3770
Decamethylcyclopentasiloxane (cyclic monomer)
FT-0665531
S05475
Decamethylcyclopentasiloxane, analytical standard
Q414350
decamethyl-1,3,5,7,9,2,4,6,8,10-pentaoxapentasilecane
UNII-NMQ347994Z component XMSXQFUHVRWGNA-UHFFFAOYSA-N
Cyclomethicone 5, United States Pharmacopeia (USP) Reference Standard
2,2,4,4,6,6,8,8,10,10-Decamethyl-1,3,5,7,9,2,4,6,8,10-pentaoxapentasilecane #
D5 Cyclomethicone, Pharmaceutical Secondary Standard; Certified Reference Material
COMPATIBILITY
Type of material
Water I
1
Ethanol (200 proof) C
Glycerine I
Octyl methoxy cinnamate C
Waxes
Stearyl alcohol C
Beeswax C
Paraffin wax C
Myristyl myristate C
Stearic acid C
Hydrocarbons
Mineral oil C
Petrolatum C
Isododecane C
Isopar H C
Polydecene C
Oils
Almond oil C
Castor oil I
Jojoba oil C
Soybean oil C
Sunflower oil C
Esters
Isopropyl myristate C
Isopropyl palmitate C
Octyl palmitate C
C12-C15 Alcohol benzoate C
Capric/caprylic triglycerides C
Octyldodecanol C
Oleyl alcohol C
Silicones
Dimethicone, 350mm2s 1 C C
Pheyl trimethicone C C
Stearyl dimethicone C C
Cetyl dimethicone C C
1
C: compatible all ratios; I: Incompatible all ratios.
Results from heating the ingredients to approximately 80°C (176°F) (care has to be taken as silicone fluid is above its flash point). All other
results obtained at 25°C (77°F)
Scientific Committee on Consumer Safety
SCCS OPINION on decamethylcyclopentasiloxane (cyclopentasiloxane, D5)in cosmetic products
The SCCS adopted this Opinion at its 9th plenary meeting on 25 March 2015
Recently many ingredients have been restricted in cosmetic products, among others: Cyclopentasiloxane (D5) and Cyclotetrasiloxane (D4). Both of them are silicones, and they are used to protect the skin and to retain moisture.
Major changes
In 2015, the Scientific Committee of Consumers Safety (SCCS) stated that the level of Cyclotetrasiloxane (D4) as an impurity of Cyclopentasiloxane (D5), should be kept as low as possible, due to the toxicity potential of D4.
At the beginning of 2017 the European Commission (EC) proposed to ban Cyclotetrasiloxane (D4) and Cyclopentasiloxane (D5) in rinse-off cosmetic products, with 0.1% or more of either substance. This ban, when officially published, is going to cover products such as shampoos, conditioners, shower gels, etc.
The European Chemicals Agency (ECHA) plans to go even further and to extend the restriction to leave on personal care products intended to remain on the skin.
This proposal is currently in public consultation.
Why are these ingredients being restricted?
Cyclotetrasiloxane (D4) is toxic to human reproduction system and it accumulates in the environment with unpredictable long-term effects.
Cyclopentasiloxane (D5) can also be harmful to the environment.
The major problem is the purity of the silicone – or the lack of it. The harmful Cyclotetrasiloxane (D4) is a common case of impurity for Cyclopentasiloxane (D5) and it is very difficult to differentiate between them.
What do the Manufacturers need to do?
Make sure that the raw materials supplier provides you with Cyclopentasiloxane (D5) with the highest purity (99%) and that it does not contain Cyclotetrasiloxane (D4)
As a precautionary measure – plan to reformulate rinse-off cosmetic products with Cyclopentasiloxane by decreasing the amount until up to 0,1%, or by replacing it with another type of silicone
Restrictions on cosmetic ingredients In the EU
Cosmetic ingredients are constantly under watch by the Scientific Committee for Consumer Safety (SCCS) and Competent Authorities.
The aim is to assess their safety and establish restrictions for the protection of human health. Silicones have been on the spot recently.
Currently the attention has turned towards one of the most widely used types – Cyclopentasiloxane. Cosmetics manufacturers and their Responsible Persons should closely follow the updates from the SCCS and keep track of the amendments to the relevant Regulations to take the right decisions to ensure compliance of their products on the EU market.
Benefits of Cylcopentasiloxane
Although cyclopentasiloxane has minimal benefits specific to the skin, it does have notable sensory properties and also helps in how the product functions.
Cylcopentasiloxane spreads easily: Silicones are known for their slippery glide and smooth feel. Rabach says cyclopentasiloxane gives products a silky smooth texture that applies easily and leaves a non-greasy finish.
Cylcopentasiloxane is inexpensive: Rabach says because cyclopentasiloxane is cheaper than other similar silicones, your products that contain it will also be more affordable as a result.
Cylcopentasiloxane evaporates quickly: Cyclopentasiloxane is volatile, so it’s often included in product formulations because it allows the products to dry faster.
Cylcopentasiloxane is lightweight: Some silicones are heavy, but this one is particularly lightweight and used when a lighter feel is desired.
This trait is especially helpful in haircare products so as not to weigh down the hair strands.
Cylcopentasiloxane disperses heavier ingredients: Cyclopentasiloxane works well when combined with heavier oils or silicones because it makes them easier to spread and provides a nice feel to the skin.
Cylcopentasiloxane seals hydration: Cyclopentasiloxane forms a seal or barrier on the skin.
This barrier protects against transepidermal water loss (TEWL), which can lead to inflammatory conditions.
Cyclopentasiloxane also works similarly when used on the hair by coating the hair shaft.
The molecular structure of silicones (large molecules with wide spaces between each molecule) means that the barrier they form is permeable, preventing the skin from “suffocating”.
Cyclopentasiloxane
THE GOOD:Cyclopentasiloxane helps to improve the texture of products, giving them a silky feel. They also help to deliver key ingredients to the skin and protect the skin from moisture loss.
THE NOT SO GOOD:Often will need to be combined with heavier silicones to help improve the thickness and spreadability of the product.
WHO IS IT FOR?
All skin types except those that have an identified allergy to it.
SYNERGETIC INGREDIENTS:Works well with most ingredients.
KEEP AN EYE ON: Other names such as decamethylcyclopentasiloxane or D5 cyclomethicone.
What Are The Benefits of Cyclopentasiloxane?
Cyclopentasiloxane is a multifunctional ingredient in skincare and cosmetic formulations. The main benefit is that it helps to improve the texture and sensory feel of the product on the skin. However, it also has many other added benefits.
Congested skin types
There is a general misconception that silicone-containing products cause breakouts. These claims remain unsubstantiated by peer-reviewed research. Studies have determined that most silicone products are non-comedogenic (not clogging) and allow the skin to breathe. Silicones and cyclomethicones do not enter the pores, where the formation of blemishes occur, and cyclopentasiloxane evaporates, reducing the barrier effect on the skin. This misconception comes from anecdotal evidence, and while that can be a useful tool for driving areas of research, it does not replace an in-depth study.
One explanation for the anecdotal evidence that suggests that silicone products worsen congested skin types is that they may trap sweat or other skincare products that potentially cause breakouts, closer to the skin. This theory hasn’t been tested but has some validity given the function of silicones.
To avoid this potential side effect, it is best to make sure you cleanse the skin after exercising and to check the ingredients in your other skincare products to see if they could be contributing to the breakouts.
Sensitivity
It is believed that cyclopentasiloxane may have some capacity to reduce the appearance of wrinkles, actually help in the healing of skin blemishes and calm the visible effects of rosacea. Cyclopentasiloxane is an emollient that soothes and softens the skin by keeping moisture locked in. This characteristic helps to prevent water loss and maintain the integrity of the skin’s natural barrier. Protecting or preserving the skin’s natural barrier is an essential part of keeping sensitivity issues at bay. Disruption of the skin’s natural barrier is considered to be linked with skin conditions such as eczema, dermatitis, and psoriasis.
If you have sensitive skin, be mindful of the other ingredients in your product that may irritate, such as fragrance, because the cyclopentasiloxane will deliver these ingredients effectively to the skin. In some cases, minor irritation may occur from the use of silicones, but it’s not usually the source of sensitivity in a product.
Is Cyclopentasiloxane Safe?
Cyclopentasiloxane is considered to be a safe ingredient for its indicated uses in skincare and cosmetics. The Cosmetic Ingredient Review Expert Panel, a US organization that determines the safety of cosmetic and skincare ingredients, concluded in 1991 that compounds containing cyclopentasiloxane safe for use. Further reviews conducted in 2005 supported its use.
Environment
One issue with cyclopentasiloxane is its potential impact on the environment. Cyclopentasiloxane doesn’t readily degrade. This may have a disrupting effect on the environment. As a precautionary measure, the European Union in 2020, limited concentrations of cyclopentasiloxane in products to 0.1%. 0.1% is generally the concentration it is used at, so this is unlikely to affect the formulation of your favorite skincare products if other countries adopt this same policy.
What is it used for?
D5 is known for being able to evaporate and dry quickly. Silicones are also known to repel water and glide easily. This is why they are commonly used as ingredients in lubricants and sealants.
They are also known to form a protective barrier on the skin and hair. This can help you detangle your hair, prevent breakage, and reduce frizz.
D5 can be found in a wide range of personal care products. Examples include:
hair spray
sunscreen
antiperspirant
deodorant
hair conditioner
shampoo
hair detangling products
waterproof mascara
foundation
eyeliner
concealer
moisturizer with SPF
eye shadow
hairstyling gel and lotion
lipstick
It sometimes appears on a label as decamethylcyclopentasiloxane or D5. It may also be put under the broader category name of cyclomethicone.
It’s different from another siloxane known as dimethicone or polydimethylsiloxane (PDMS).
Is it safe?
One of the main benefits of D5 compared to similar ingredients is that it’s less expensive. This helps lower the cost of your favorite products. Of course, the lower cost means there’s an incentive for manufacturers to use it instead of other ingredients, regardless of its safety or environmental impact.
Safety concerns in humans
The Environmental Working Group (EWG) found that there’s a low concern that D5 can be considered an endocrine disrupter, or something that can disturb the normal functioning of your hormones. It could be more of a concern when it’s used at concentrations higher than what is typically used in cosmetics. The Cosmetic Ingredient Review Expert Panel considers the chemical safe to use at existing concentrations.
To be an endocrine disruptor, a chemical must get into the body. A 2012 study published in the International Journal of Toxicology found that D5 isn’t absorbed into the skin. A 2016 study confirmed that it rapidly evaporates after contacting the skin with very little of the chemical entering the body.
If inhaled, it’s either quickly exhaled or broken down and excreted in urine. This means that accumulation of this chemical in the body is unlikely.
D5 also wasn’t found to cause skin irritation or sensitization in humans. When used in sunscreens and lotions, research shows it may even prevent irritation in patients with skin conditions like rosacea.
Environmental hazards
There is some controversy surrounding the environmental impact of this ingredient. Chemicals used in hair and skin products can make their way into the environment when they’re rinsed down the drain. These products may then accumulate and harm fish and other wildlife.
Cyclopentasiloxane was once considered hazardous to aquatic wildlife. It was found in laboratory studies to be bio-accumulative in some aquatic animals. This prompted a Canadian review board to conduct more research about the environmental impact of this chemical.
A 2011 review concluded that D5 didn’t pose a danger to the environment. The review board found no evidence of toxicity to any organism. The board also didn’t find evidence that the chemical can build up to high enough concentrations to cause problems in animals.
A 2013 study found that the chemical evaporates during typical use. Only a very small fraction of the chemical finds its way down the drain and into the environment. This amount is considered negligible by the study authors.
Contrary to the earlier studies, recent evaluation by the European Union regarding environmental accumulation of D5 has resulted in limits on concentrations used in wash-off cosmetics to less than 0.1%, effective January 31, 2020.
The bottom line
Products containing cyclopentasiloxane can be used safely on your hair and skin with minimal personal risk. It helps your skin and hair products dry quickly and spread more easily. It can make the hair feel silky without weighing it down.
Though there is a concern that this ingredient can disrupt hormones in your body, research shows that it doesn’t get absorbed into the skin in high enough doses to cause harm.
It is possible that D5 could accumulate in water supplies when used in concentrations above 0.1% and when washed off before evaporating. This possibility has led to increased regulation of its use in some countries.