What is Sodium Thioglycolate?
Sodium Thioglycolate is the sodium salt of thioglycolic acid, with the chemical formula HSCH₂COONa.
It is an organic compound used in various applications, notably cosmetics.
What are the common names for this chemical?
Besides Sodium Thioglycolate, it is also commonly known as Sodium Mercaptoacetate. Sometimes, the acid form (Thioglycolic Acid) is discussed in related contexts.
Does Sodium Thioglycolate have an odor?
Yes, it typically has a distinct, unpleasant sulfurous odor, often described as “rotten egg-like,” especially in solution or when degrading.
What is the primary function of Sodium Thioglycolate in cosmetics?
Its primary functions are as a depilating agent (hair removal) and a hair waving/straightening agent. It can also act as an antioxidant or reducing agent in some formulations.
How does Sodium Thioglycolate work for hair removal?
It works by chemically breaking the disulfide bonds (keratin bonds) in the hair shaft. This weakens the hair structure, allowing it to be easily wiped or rinsed away from the skin surface.
How does Sodium Thioglycolate work in permanent wave or straightening products?
Similarly to hair removal, it breaks the disulfide bonds in hair keratin. This allows the hair to be reshaped (e.g., around a curler or straightened). A subsequent neutralization step (often using an oxidizing agent like hydrogen peroxide) reforms the disulfide bonds in the new shape, making the style semi-permanent.
Is Sodium Thioglycolate safe for use in cosmetics?
When used according to directions and within regulated concentration limits, it is considered safe for its intended cosmetic purposes (hair removal, waving). However, it can be irritating, especially at higher concentrations or with prolonged contact.
What are the regulated concentration limits for Sodium Thioglycolate in cosmetics?
Regulations vary by region (e.g., EU, FDA). Generally, for depilatories, the concentration (calculated as thioglycolic acid) is often limited to around 5-6%, and for hair waving/straightening products, it might range up to 11-12%, with specific pH requirements. Always check local regulations.
Can Sodium Thioglycolate cause skin irritation?
Yes, it can cause skin irritation, redness, or even chemical burns, particularly if left on the skin for too long, used at too high a concentration, or applied to sensitive or broken skin. Patch testing is often recommended.
Is Sodium Thioglycolate harmful if it gets in the eyes?
Yes, it is a severe eye irritant and can cause significant damage. Contact with eyes should be avoided rigorously. Products containing it carry warnings to this effect.
What should I do if I get Sodium Thioglycolate on my skin or in my eyes?
For skin contact, rinse immediately and thoroughly with plenty of water. If irritation persists, seek medical advice. For eye contact, immediately flush eyes with copious amounts of water for at least 15 minutes, holding eyelids open, and seek immediate medical attention.
Is Sodium Thioglycolate toxic if ingested?
Yes, it is considered toxic if swallowed. Ingestion should be avoided. Keep products containing it out of reach of children.
Are there any specific storage recommendations for Sodium Thioglycolate?
It should be stored in tightly closed containers in a cool, dry, well-ventilated area, away from heat, strong acids, strong bases, and oxidizing agents. It can be sensitive to air and light.
What personal protective equipment (PPE) is recommended when handling pure Sodium Thioglycolate or concentrated solutions?
Wear appropriate protective gloves (e.g., nitrile or neoprene), safety glasses or goggles, and protective clothing. If handling powder or in situations where dust or aerosols may be generated, respiratory protection might be necessary.
Does Sodium Thioglycolate have uses outside of cosmetics?
Yes, it can be used in some industrial applications, such as in metal cleaning or recovery processes, as a reagent in analytical chemistry, or potentially in leather processing, although these are less common than its cosmetic uses.
What is the typical pH range for products containing Sodium Thioglycolate?
Cosmetic products like depilatories often have a high pH, typically ranging from pH 9 to 12.5, to enhance the efficacy of hair removal. Hair waving lotions also operate in alkaline or sometimes acidic pH ranges depending on the specific formulation.
Is Sodium Thioglycolate stable?
Sodium Thioglycolate can be sensitive to oxidation, especially by air, particularly in solution and at higher pH values or temperatures. This oxidation can reduce its effectiveness. Formulations often include stabilizers or antioxidants.
Can people be allergic to Sodium Thioglycolate?
While primary irritation is more common, allergic contact dermatitis (an allergic reaction) to thioglycolates can occur, though it’s considered less frequent than irritation. Patch testing can help identify allergies.
How is Sodium Thioglycolate produced?
It is typically produced by reacting thioglycolic acid with a sodium base, such as sodium hydroxide or sodium carbonate, under controlled conditions.
What happens to Sodium Thioglycolate in the environment?
Thioglycolates are generally expected to biodegrade in the environment. However, due to their chemical nature and potential aquatic toxicity, large releases should be prevented, and disposal should follow local regulations.
Are Sodium Thioglycolate and Thioglycolic Acid the same thing?
No, Sodium Thioglycolate is the sodium salt of Thioglycolic Acid. Thioglycolic Acid (HSCH₂COOH) is the parent acid. In cosmetic formulations, often the salt is used, but the concentration limits and activity are frequently discussed in terms of the equivalent amount of the free acid.
