MONOMETHYL ETHER OF HYDROQUINONE (MEHQ)

Monomethyl Ether of Hydroquinone (MEHQ) is a colorless to white, waxy solid with an odor of caramel and phenol. 
Monomethyl Ether of Hydroquinone (MEHQ) is a combustible solid. 
Monomethyl Ether of Hydroquinone (MEHQ) is used as an inhibitor for acrylic monomers and as a stabilizer for chlorinated hydrocarbons, ethyl cellulose, and UV inhibitors.

CAS Number: 150-76-5
Molecular Formula: C7H8O2
Molecular Weight: 124.14
EINECS Number: 205-769-8

Synonyms: N-(2-hydroxyethyl)prop-2-enamide, N-(2-HYDROXYETHYL)ACRYLAMIDE (STABILIZED WITH MEHQ), RefChem:825485, 619-814-8, 700-169-7, N-(2-Hydroxyethyl)acrylamide, 7646-67-5, MFCD11110645, n-hydroxyethylacrylamide, N-Hydroxyethyl acrylamide, HEAA, N-Hydroxyethyl acrylamide(heaa),98%, 2-Propenamide, N-(2-hydroxyethyl)-, 28156-60-7, N-2-hydroxyethylacrylamide, SCHEMBL14966, CH2=CH(CO)NHCH2CH2OH, orb2944024, SCHEMBL4578905, SCHEMBL13341773, DTXSID80997843, N-(2-Hydroxyethyl)-2-propenamide, AKOS009531781, FH31187, AS-59388, SY053669, DS-017584, CS-0146430, H1262, NS00009764, D78367, EN300-103180, F619614, N-(2-Hydroxyethyl)acrylamide, (stabilized with MEHQ), N-(2-HYDROXYETHYL)ACRYLAMIDE(STABILIZED WITH MHQ), N-Hydroxyethyl acrylamide, contains 1,000 ppm monomethyl ether hydroquinone as stabilizer, 97%, Eastman HQMME;ethermonomethyliqued’hydroquinone;Hqmme;Hydroquinone methyl ether;hydroquinonemethylether;Leucobasal;Leucodine b;leucodineb

Monomethyl Ether of Hydroquinone (MEHQ) is a light-colored crystalline solid. 
Its chemical term is 4-Methoxyphenol. 
As a stabilizer, it avoids premature polymerization in acrylates, methacrylates, and other monomers. 

Monomethyl Ether of Hydroquinone (MEHQ)s molecular formula is C7H8O2 and CAS number is 150-76-5.
Monomethyl Ether of Hydroquinone (MEHQ) achieves this by neutralizing free radicals that may induce undesirable polymerization. 
In doing so, it safeguards sensitive chemicals when stored or transported, thus ensuring that they are stable and safe to apply.

Monomethyl Ether of Hydroquinone (MEHQ), also known as 4-methoxyphenol or hydroquinone monomethyl ether, is an aromatic phenolic compound commonly used as a stabilizer. 
It prevents premature polymerization of acrylate and methacrylate monomers during storage and transport. 
Monomethyl Ether of Hydroquinone (MEHQ) is typically added in very small concentrations because even trace levels are effective at inhibiting radical polymer growth.

Monomethyl Ether of Hydroquinone (MEHQ) works by scavenging free radicals that would otherwise trigger polymer formation. 
Its structure contains a phenolic –OH group and a methoxy group, which together provide controlled antioxidant properties. 
This makes it widely used in resin, adhesive, and UV-curable formulation industries.

Monomethyl Ether of Hydroquinone (MEHQ) appears as a white to off-white crystalline solid with mild odor and good stability under normal conditions. 
It dissolves in common organic solvents and displays moderate acidity due to its phenolic function. 
Because it is an inhibitor, it is essential for safely storing reactive monomers like hydroxyethyl acrylamide, MMA, and other acrylates.

Monomethyl Ether of Hydroquinone (MEHQ) is a colorless to white, waxy solid with an odor of caramel and phenol. 
A combustible solid. Molecular weight= 124.15;Boiling point=243℃; Freezing/Melting point=5253℃; Flash point=132℃. 
Hazard Identification (based on NFPA-704 M Rating System): Health 2, Flammability 1, Reactivity 0. Slightly soluble in water.

Monomethyl Ether of Hydroquinone (MEHQ) is an organic compound and synthetic derivative of hydroquinone. 
Monomethyl Ether of Hydroquinone (MEHQ) is also known by names such as mequinole, 4-hydroxy anisole, para-guaiacol, etc. 
Monomethyl Ether of Hydroquinone (MEHQ) is commercially manufactured by the hydroxylation of anisole or by free radical reaction between p-benzoquinone and methanol. 

Monomethyl Ether of Hydroquinone (MEHQ) is widely used in dermatology. 
Monomethyl Ether of Hydroquinone (MEHQ) is the main ingredient in topical drugs which are used for skin depigmentation. 
The drug is commonly formulated by the addition of an ethanolic solution of 2% MEHQ and 0.01% of tretinoin by mass.

The drug is generally prescribed by dermatologists for the treatment of solar liver spots, age spots, or solar lentigines. 
Low dosage of Monomethyl Ether of Hydroquinone (MEHQ) can be used in combination with Q- switched laser to de-pigment the skin of patients having disseminated idiopathic vitiligo.
Monomethyl Ether of Hydroquinone (MEHQ) is a phenolic antioxidant and free-radical scavenger that plays a critical role in stabilizing reactive monomers such as acrylates, methacrylates, and vinyl compounds. 

Monomethyl Ether of Hydroquinone (MEHQ) acts by capturing peroxide-derived radicals or other initiating species before they can propagate polymer chains, thereby preventing runaway polymerization. 
Because polymerizable monomers are often stored, shipped, and processed in bulk, Monomethyl Ether of Hydroquinone (MEHQ) enables safe handling by providing long-term stabilization even at low concentrations.

Its chemical structure — a hydroquinone molecule with one hydroxyl group replaced by a methoxy group — offers a balance between reactivity and stability. 
The phenolic hydrogen remains sufficiently active to react with radicals, while the methoxy substitution improves oxidative stability and reduces over-reactivity compared to hydroquinone itself. 
This structural design makes MEHQ more selective and safer to use, especially in industrial monomer storage tanks and sealed transport containers.

Monomethyl Ether of Hydroquinone (MEHQ) also exhibits controlled inhibitor behavior dependent on oxygen presence, meaning a minimal amount of dissolved oxygen is needed for optimal activity. 
This property prevents accidental loss of inhibition under anaerobic conditions, offering a built-in safety margin for materials like hydroxyethyl acrylamide or methyl methacrylate. 
Monomethyl Ether of Hydroquinone (MEHQ) is frequently integrated into UV-curable coatings, adhesives, inks, and elastomers, ensuring shelf-life stability before intentional curing begins.

Melting point: 56 °C
Boiling point: 243 °C (lit.)
Density: 1.55 g/cm³
Vapor density: 4.3 (vs air)
Vapor pressure: <0.01 mm Hg (20 °C)
Refractive index: 1.5286 (estimate)
Flash point: >230 °F
Storage temperature: Store below +30 °C
Solubility: Soluble in acetone, ethyl acetate, ethanol, ether, benzene, and carbon tetrachloride
Form: Liquid
pKa: 10.21 (25 °C)
Color: Clear, colorless to pale yellow
Odor: Phenolic (at ~1.0 % in dipropylene glycol)
pH: 5.1 (30 g/L, H₂O, 20 °C)
Odor threshold: 0.0027 ppm
Water solubility: 40 g/L (25 °C)
BRN: 507924
Exposure limits: ACGIH TWA 5 mg/m³; NIOSH TWA 5 mg/m³
Stability: Stable; combustible; incompatible with halogens and oxidizing agents
InChIKey: NWVVVBRKAWDGAB-UHFFFAOYSA-N
LogP: 1.3 (20 °C)

Monomethyl Ether of Hydroquinone (MEHQ) is a member of phenols and a member of methoxybenzenes. 
Monomethyl Ether of Hydroquinone (MEHQ) has a role as a metabolite.
Monomethyl Ether of Hydroquinone (MEHQ) may be used in the synthesis of butylated hydroxy anisoles via alkylation with methyl tert-butyl ether over a non-zeolitic solid acidic catalyst. 

This process is eco-friendly when compared to the Friedel-Crafts alkylation reaction. 
Monomethyl Ether of Hydroquinone (MEHQ) may also react with aqueous nitrous acid to form 2-nitro-4-methoxyphenol and benzoquinone in varying ratios depending on the reaction conditions. 
Monomethyl Ether of Hydroquinone (MEHQ) can be used as a building block in designing β-cyclodextrin 4-methoxyphenol conjugates that can be potential ligands for drug complexation.

Store in tightly closed containers in a cool, well-ventilated area. 
Sources of ignition, such as smoking and open flames, are prohibited where Monomethyl Ether of Hydroquinone (MEHQ) is used, handled, or stored in a manner that could create a potential fire or explosion hazard.
If Monomethyl Ether of Hydroquinone (MEHQ) gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 min, occasionally lifting upper and lower lids. 

Monomethyl Ether of Hydroquinone (MEHQ) contacts the skin, remove contaminated clothing and wash immediately with soap and water. 
If Monomethyl Ether of Hydroquinone (MEHQ) has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. 
Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. 

Give large quantities of water and induce vomiting. Do not make an unconscious person vomit.
Monomethyl Ether of Hydroquinone (MEHQ) is also widely used as a polymerization inhibitor in the manufacturing of various monomers such as acrylics, methacrylics and other acrylates, vinyl acetate monomers, etc., along with unsaturated polyesters. 
Monomethyl Ether of Hydroquinone (MEHQ) is also used as a stabilizer for cosmetics, liquid detergents, and cellulose materials. 

Besides these applications, Monomethyl Ether of Hydroquinone (MEHQ) is also used in the ink industry as a polymerization inhibitor. 
Monomethyl Ether of Hydroquinone (MEHQ) is the building block for agrochemical and organic chemical manufacturing industries. 
There are certain regulations on the exposure limit for Monomethyl Ether of Hydroquinone (MEHQ). 

According to the National Institute for Occupational Safety and Health, the recommended exposure limit for Monomethyl Ether of Hydroquinone (MEHQ) is 5mg/m3 for an 8-hour workday.
Physically, Monomethyl Ether of Hydroquinone (MEHQ) is a white-to-light beige crystalline solid with good solubility in organic solvents and mild solubility in water. 
It has a relatively high decomposition temperature and is stable under normal indoor storage conditions when protected from strong oxidizers. 

Due to its active phenolic group, handling precautions such as gloves, ventilation, and dust control are recommended to avoid skin or respiratory irritation during weighing or mixing.
Commercially, it is valued for being highly efficient — only 50–1000 ppm is typically necessary for large volume monomer stabilization. 
This makes Monomethyl Ether of Hydroquinone (MEHQ) both cost-effective and preferred by regulatory frameworks because lower additive loading reduces downstream purification requirements. 

In short, it is a critical industrial safety component, enabling the global polymer industry to manage reactive monomers reliably and securely from production to final formulation.
Polymers are finding new applications, due to which, their demand is increasing day by day. 
This increasing demand for polymers is leading to the growth of the MEHQ industry. Growing population and changing fashion trends are boosting the textile and leather industries, owing to which, the MEHQ market is also escalating. 

Monomethyl Ether of Hydroquinone (MEHQ) is mainly used as an intermediate in agrochemicals and organic chemical industries. 
Increasing consumption of agrochemicals and organic chemicals is boosting the Monomethyl Ether of Hydroquinone (MEHQ) market.
Monomethyl Ether of Hydroquinone (MEHQ) also finds application in petrochemical industries, and the growth of the petrochemical industries is leading to an increase in the demand for MEHQ in the market. 

Developments in medical science are generating new applications for Monomethyl Ether of Hydroquinone (MEHQ) in the medical field. 
Monomethyl Ether of Hydroquinone (MEHQ) is also used in the pharmaceutical and cosmetic industries, and the increased demand for pharmaceutical and cosmetic products will lead to an increase in the consumption of MEHQ.
Besides these applications, MEHQ is also used as an additive in ink, adhesives, tonners, sealants, liquid detergents, etc. 

The increasing production of these products will increase the demand for Monomethyl Ether of Hydroquinone (MEHQ). 
In certain regions, there are regulations being imposed on the exposure limit of Monomethyl Ether of Hydroquinone (MEHQ). 
Companies are also searching for alternative for Monomethyl Ether of Hydroquinone (MEHQ). 

Uses Of Monomethyl Ether of Hydroquinone (MEHQ):
Monomethyl Ether of Hydroquinone (MEHQ) is an active ingredient and used in dermatology. 
It is employed as a pharmaceutical drug in skin depigmentation. 
Monomethyl Ether of Hydroquinone (MEHQ) is used as polymerization inhibitors. 

For example, in the radical polymerization of acryaltes and styrene monomers. 
Monomethyl Ether of Hydroquinone (MEHQ) is also used as an intermediate in the preparationagrochemicals, liquid crystals. 
It acts as a stabilizer for the formulation of inks, toners and adhesives. 

Monomethyl Ether of Hydroquinone (MEHQ) is mainly used as an additive for textile and leather industries.
It is widely used as a polymerization inhibitor in acrylates, methacrylates, and vinyl monomers. 
By scavenging reactive radicals, it prevents accidental polymer formation during storage and transportation. 

This ensures long-term product stability and industrial safety in bulk monomer handling.
It is utilized in the production and packaging of UV-curable coatings, inks, and adhesives. 
Since these formulations polymerize rapidly under light exposure, MEHQ maintains stability until intentional curing occurs. 

This allows precise control over processing and application timing.
Monomethyl Ether of Hydroquinone (MEHQ) is incorporated into resin and composite manufacturing to avoid premature gelling. 
Even small concentrations effectively stop chain propagation events that could ruin entire production batches. 

As a result, manufacturers achieve higher yields and better consistency in final materials.
It supports medical and dental materials that rely on radical-initiated curing systems. 
Monomethyl Ether of Hydroquinone (MEHQ) keeps components stable in sealed containers until they are mixed or activated at the point of use. 

This leads to improved usability and extended shelf life of sensitive products.
It is used in adhesive and sealant formulations requiring long-term storage and controlled cure onset. 
By minimizing spontaneous viscosity increase, Monomethyl Ether of Hydroquinone (MEHQ) preserves processability over months of warehousing. 

This stabilizing function is essential for maintaining product performance in global supply chains.
Monomethyl Ether of Hydroquinone (MEHQ) appears in elastomer and synthetic rubber systems where radical polymerization must be delayed until vulcanization or curing stages. 
The inhibitor effect prevents premature network formation inside mixing equipment. This helps avoid operational hazards and material waste.

Monomethyl Ether of Hydroquinone (MEHQ) is used in bulk transportation of reactive monomers via drums, ISO tanks, and pipeline systems. 
Monomethyl Ether of Hydroquinone (MEHQ) prevents polymer buildup that could clog valves or cause dangerous pressure increases. 
This ensures compliance with international safety standards during global logistics.

It plays a key role in acrylic fiber and superabsorbent polymer manufacturing. 
During high-volume production, it maintains monomer fluidity until the controlled polymerization phase begins. 
This helps optimize production speed, quality consistency, and raw-material utilization.

It assists in emulsion and dispersion polymerization reactions where early nucleation could destabilize particle formation. 
By delaying radical growth, MEHQ helps maintain controlled particle size distribution. 
This directly improves the mechanical and optical properties of the resulting polymer dispersions.

Monomethyl Ether of Hydroquinone (MEHQ) is valuable for monomer purification and distillation operations. 
Its radical-inhibiting properties prevent polymer fouling in heated equipment. 
This reduces downtime, cleaning frequency, and the risk of thermal runaway reactions.

Monomethyl Ether of Hydroquinone (MEHQ) is used in research environments where sensitive radical polymerization studies require strict control. 
Only trace amounts are needed to stop chain propagation and study reaction initiation precisely. 
This helps scientists design more efficient catalysts and initiator systems.

It can function as a quality-control safeguard in packaged monomer products. 
Stability testing often includes Monomethyl Ether of Hydroquinone (MEHQ)-treated samples to verify inhibitor performance under different temperatures and light conditions. 
This ensures that products remain safe and functional throughout their shelf life.

Safety Profile Of Monomethyl Ether of Hydroquinone (MEHQ):
It can cause skin irritation upon contact, especially in the presence of moisture or heat. 
Extended exposure may lead to redness and dryness. 
Protective gloves should always be worn when handling the solid or its dust.

Monomethyl Ether of Hydroquinone (MEHQ) may produce eye irritation if particles or dust become airborne. 
Contact can result in temporary discomfort, tearing, and redness. 
Safety goggles are strongly recommended during weighing, mixing, or transferring.

Inhalation of dust or vapors can irritate the respiratory tract. 
Symptoms may include coughing or a slight burning sensation in the throat. 
Monomethyl Ether of Hydroquinone (MEHQ) use of proper ventilation or a fume hood minimizes inhalation risks.

Ingestion of Monomethyl Ether of Hydroquinone (MEHQ) can cause gastrointestinal discomfort or harmful systemic effects. 
Accidental swallowing requires prompt medical evaluation. 
Food and beverages should never be present in work areas handling the compound.

Monomethyl Ether of Hydroquinone (MEHQ) is considered a combustible solid, capable of burning if exposed to ignition sources. 
Fine powder may also form combustible dust-air mixtures under certain conditions. 
Monomethyl Ether of Hydroquinone (MEHQ) may undergo oxidation when exposed to strong oxidizing agents. 

This can lead to more aggressive decomposition and increased hazard potential. 
Chemical storage must avoid incompatible materials to ensure stability.

Repeated or prolonged exposure may affect blood and liver function due to phenolic metabolism pathways. 
Although toxicity depends on dose and duration, chronic handling without protection is discouraged. Good hygiene and minimized contact time are essential.