ETHOXYQUIN

Ethoxyquin is a quinoline that is 1,2-dihydroquinoline bearing three methyl substituents at position 2, 2 and 4 as well as an ethoxy substituent at position 6. 
Ethoxyquin is a member of quinolines and an aromatic ether.
Ethoxyquin is a quinoline-based antioxidant used as a food preservative in certain countries and originally to control scald on pears after harvest (under commercial names such as "Stop-Scald").

CAS Number: 91-53-2
Molecular Formula: C14H19NO
Molecular Weight: 217.31
EINECS Number: 202-075-7

Synonyms: ethoxyquin, 91-53-2, 6-Ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, Ethoxyquine, Santoquin, Santoquine, Niflex, Antioxidant EC, Santoflex A, Santoflex AW, Stop-Scald, Dawe's nutrigard, Nix-Scald, Nocrack AW, Quinol ED, Aries Antox, Permanax 103, Amea 100, Niflex D, Antage AW, Nocrac AW, Ethoxychin, Alterungsschutzmittel EC, Ethoxyquin [ISO], Quinoline, 6-ethoxy-1,2-dihydro-2,2,4-trimethyl-, Santoquine (VAN), Usaf B-24, 1,2-Dihydro-6-ethoxy-2,2,4-trimethylquinoline, 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, Ethoxychin [Czech], Santoflex, Antox, Caswell No. 427D, NSC-6795, 1,2-Dihydro-2,2,4-trimethyl-6-ethoxyquinoline, 2,2,4-Trimethyl-6-ethoxy-1,2-dihydroquinoline, CCRIS 2513, HSDB 400, SantoquinEQ, 6-ETMDQ, EINECS 202-075-7, EPA Pesticide Chemical Code 055501, UNII-9T1410R4OR, DTXSID9020582, CHEBI:77323, AI3-17715, 9T1410R4OR, ETHOXYQUIN [MI], ETHOXYQUIN [FCC], ETHOXYQUIN [HSDB], ETHOXYQUIN [MART.], 6-(ethyloxy)-2,2,4-trimethyl-1,2-dihydroquinoline, DTXCID70582, NSC 6795, Ethyl 2,2,4-trimethyl-1,2-dihydro-6-quinolinyl ether, E 324, ETHOXYQUIN (MART.), 2,2, 4-Trimethyl-6-ethoxy-1,2-dihydroquinoline, 6-Ethoxy-1, 2-dihydro-2,2,4-trimethylquinoline, 6-Ethoxy-2,2,4-trimethyl-1, 2-dihydroquinoline, 6-Ethoxy-1,2-dihydro-2,2,4-trimethyl-Quinoline, 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, 9CI, 8CI, 1,2-DIHYDRO-2,2,4-TRIMETHYLQUINOLIN-6-YL ETHYL ETHER, StopScald, NixScald, RALUQUIN, Pesticide Code 055501, 1,2Dihydro2,2,4trimethyl6ethoxyquinoline, 1,2Dihydro6ethoxy2,2,4trimethylquinoline, 2,2,4Trimethyl6ethoxy1,2dihydroquinoline, 6Ethoxy1,2dihydro2,2,4trimethylquinoline, 6Ethoxy2,2,4trimethyl1,2dihydroquinoline, Quinoline, 6ethoxy1,2dihydro2,2,4trimethyl, 1,2-dihydro-2,2,4-trimethyl-6-quinolyl ethyl ether, ethyl 2,2,4-trimethyl-1,2-dihydro-6-quinolyl ether, 2,2,4-TRIMETHYL-1,2-DIHYDRO-6-ETHOXYQUINOLINE, 202-075-7, decipouijurfoj-uhfffaoysa-n, 6-ethoxy-2,2,4-trimethyl-1H-quinoline, EMQ, EQ, CAS-91-53-2, NCGC00016348-02, E324, MFCD00023883, Prestwick_1064, Ethoxyquin (Standard), Spectrum_001214, Prestwick0_000765, Prestwick1_000765, Prestwick2_000765, Prestwick3_000765, Spectrum2_001384, Spectrum3_001423, Spectrum4_000404, Spectrum5_001530, SCHEMBL21601, BSPBio_000810, BSPBio_003126, KBioGR_000668, KBioSS_001694, MLS001055488, BIDD:GT0822, DivK1c_000183, SPECTRUM1500998, SPBio_001368, SPBio_002749, BPBio1_000892, CHEMBL172064, SCHEMBL11806181, HMS500J05, HY-B1425R, KBio1_000183, KBio2_001694, KBio2_004262, KBio2_006830, KBio3_002346, NSC6795, NINDS_000183, HMS1570I12, HMS1923K03, HMS2097I12, HMS3714I12, HMS5084M14, HMS6018D16, 1,2,4-trimethyl-6-ethoxyquinoline, HY-B1425, 6-Ethoxy-1,2,4-trimethylquinoline, Tox21_110388, Tox21_201336, Tox21_300328, CCG-39002, Ethoxyquin, >=75% (capillary GC), s5369, SBB012680, STK772149, AKOS000121441, CS-8200, FE22911, IDI1_000183, NCGC00016348-01, NCGC00016348-03, NCGC00016348-04, NCGC00016348-05, NCGC00016348-06, NCGC00016348-07, NCGC00016348-08, NCGC00016348-09, NCGC00016348-15, NCGC00090792-01, NCGC00090792-02, NCGC00090792-03, NCGC00090792-04, NCGC00090792-05, NCGC00254395-01, NCGC00258888-01, AC-11742, AS-14741, SMR000686069, DB-057260, Ethoxyquin, Vetec(TM) reagent grade, 75%, ST4083901, WLN: T66 BM CHJ C1 C1 E1 HO2, E0237, NS00009586, 2,4-Trimethyl-6-ethoxy-1,2-dihydroquinoline, 6-Ethoxy-2,4-trimethyl-1,2-dihydroquinoline, EN300-21213, Ethoxyquin, PESTANAL(R), analytical standard, F85585, SR-01000854319, Q1657816, SR-01000854319-2, BRD-K56792340-001-05-8, BRD-K56792340-001-13-2, Z104494382, A10AE280-05F4-4846-ACAE-D565B0D263A2, Ethyl 2,2,4-trimethyl-1,2-dihydro-6-quinolinyl ether #, 6-Ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline [Antioxidant for rubber], 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline;1,2-Dihydro-2,2,4-trimethyl-6-ethoxyquinoline;1,2-Dihydro-6-ethoxy-2,2,4-trimethylquinoline, 1,2-dihydro-2,2,4-trimethyl-6-ethoxyquinoline;2,2,4-trimethyl-6-ethoxy-1,2-dihydroquinoline;6-ethoxy-1,2-dihydro-2,2,4-trimethyl-quinolin;6-Ethoxyl-2,2,4-trimethyl-1,2-dihydrquinoline;amea100;antageaw;AntioxidantAW;antioxidantec

Ethoxyquin is used as an antioxidant in animal feed and caused contact dermatitis in a worker at an animal feed mill.
Ethoxyquin has a role as a herbicide, an UDP-glucuronosyltransferase activator, a neuroprotective agent, a Hsp90 inhibitor, a genotoxin, a food antioxidant, a geroprotector and an antifungal agrochemical. 
Ethoxyquin is used as a preservative in some pet foods to slow the development of rancidity of fats. 

Ethoxyquin is also used in some spices to prevent color loss due to oxidation of the natural carotenoid pigments.
Ethoxyquin is a quinoline-based antioxidant used as a food preservative in certain countries and originally to control scald on pears after harvest.
Ethoxyquin was developed by Monsanto in the 1950s.

Ethoxyquin was initially registered as a pesticide in 1965 as an antioxidant used as a deterrent of scald in pears through post-harvest indoor application via a drench and/or impregnated wrap.
Ethoxyquin is a synthetic antioxidant primarily used as a preservative to prevent the oxidation and spoilage of fats and oils in various industrial and food products, helping to extend their shelf life and maintain quality. 
Chemically, Ethoxyquin is classified as a quinoline derivative, specifically 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, and appears as a yellowish powder that is effective at low concentrations. 

Ethoxyquin was first developed and introduced in the mid-20th century and has since been widely applied in the preservation of animal feed, especially fish meal and pet foods, where it helps to prevent rancidity caused by exposure to oxygen and light.
Ethoxyquin was initially registered as a pesticide in 1965 as an antioxidant used as a deterrent of scald in pears through post-harvest indoor application via a drench and/or impregnated wrap.
As an antioxidant to control the browning of pears, ethoxyquin is approved in the United States[3] and in the European Union.

In the United States, it is approved for use as an animal feed additive and is limited as a food additive to use only in the spices chili powder, paprika, and ground chili.
Ethoxyquin is not permitted for use as food additive in Australia[citation needed] nor within the European Union.
Ethoxyquin is allowed in the fishing industry in Norway and France as a feed stabilizer, so is commonly used in food pellets fed to farmed salmon.

Norway made this practice illegal when the EU suspended authorization in 2017 and in accordance with the suspension utilized a transition period which allowed the sale of feed containing ethoxyquin until December 31, 2019, after this date it was illegal to sell feed containing ethoxyquin. 
Feed containing ethoxyquin had to be used by June 20, 2020.
Ethoxyquin is used in pellets fed to chickens on chicken farms.

In 2017, the EU suspended authorization for use as a feed additive, with various dates between 2017 and 2019 for final allowance of sale of goods so that alternatives may be phased in.
Ethoxyquin was authorised in the EU as a feed additive for all animal species and categories until 2017, for its antioxidant properties. 
In addition, it is used to prevent spontaneous combustion of fish meal during transportation by sea.

Ethoxyquin is a synthetic antioxidant that is used primarily in animal feed (such as aquaculture and pet food).
Ethoxyquin is an antioxidant that protects and maintains the quality of the omega-3 fatty acids in sh meal, particularly during transport and storage.
Ethoxyquin is a synthetic antioxidant (articially manufactured from other elements) that is approved for dierent uses.

Ethoxyquin is an antioxidant that protects and maintains the quality of the omega-3 fatty acids in fish meal, particularly during transport and storage. 
According to the Norwegian National Institute of Nutrition and Seafood Research (NIFES), ethoxyquin exposure has not been found to have any effect on humans.  
Ethoxyquin is a synthetic chemical compound belonging to the quinoline family, and it functions primarily as an antioxidant that prevents the oxidation of fats, oils, and other susceptible organic materials. 

Its molecular structure, identified as 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, allows it to effectively interrupt free radical chain reactions, which are responsible for the degradation and rancidity of lipids when exposed to air, heat, or light. 
Because of this property, ethoxyquin is extensively used in the agricultural sector, especially in animal feed production, where it helps to preserve the nutritional quality of feed ingredients such as fish meal, meat meal, and poultry by-products by protecting their oils and fats from oxidative spoilage during storage and transport.

Melting point: <0 °C
Boiling point: 123–125 °C
Density: 1.03 g/mL at 20 °C (lit.)
Vapor pressure: 0.035 Pa at 25 °C
Refractive index: 1.569–1.571
Flash point: 137 °C
Storage temp.: 2–8 °C
Solubility: Ethanol: 50 mL/L, clear, brown
Form: Liquid
pKa: 5.02 ± 0.70 (Predicted)
Color: Yellow to Very Dark Brown
Water solubility: <0.1 g/100 mL at 20 °C
Merck: 14,3753
BRN: 158223
Stability: Stable. Combustible. Incompatible with oxidizing agents and strong acids. Polymerizes if heated. May polymerize upon exposure to light and air.
InChIKey: DECIP

Ethoxyquin is used as an antioxidant in animal feed and caused contact dermatitis in a worker at an animal feed mill
While ethoxyquin is highly effective at preventing oxidative damage, concerns have been raised about its potential toxicity and safety, leading to regulations limiting its allowable concentrations in food and feed products. 
Studies have explored its effects on animal and human health, particularly regarding possible allergic reactions, accumulation in tissues, and long-term exposure risks. 

Nonetheless, when used within established regulatory limits, ethoxyquin remains a valuable and widely used antioxidant in multiple industries, contributing significantly to product preservation and stability.
Ethoxyquin is also used in the rubber and plastic industries as an antioxidant additive to protect polymers and elastomers from degradation due to heat and oxygen during processing and storage. 
This protection helps maintain the physical properties and performance of materials such as tires, conveyor belts, and various molded rubber goods. 

Additionally, ethoxyquin has been used as a pesticide additive to protect crops and prevent spoilage during storage, although its use in food products intended for human consumption is regulated and restricted in many countries due to safety concerns.
Ethoxyquin is an aromatic from the group of quinolines.
Ethoxyquin is a synthetic antioxidant that is included in some pet foods as a preservative to protect fats and fat-soluble vitamins from turning rancid.

Ethoxyquin, also known as e 324, belongs to the class of organic compounds known as hydroquinolones.
Hydroquinolones are compounds containing a hydrogenated quinoline bearing a ketone group.
Ethoxyquin has the unique property of being able to dissolve in both aqueous- and oil phases, depending on pH.

A quinoline that is 1,2-dihydroquinoline bearing three methyl substituents at position 2, 2 and 4 as well as an ethoxy substituent at position 6.
Ethoxyquin is a Antioxidant that delays the oxidation of lipophilic Vitamins (Carotine, Xanthophylle, Vitamin A und Vitamin E).
Transparent yellow or brown viscous liquid. Discolors and stains badly. 

Soluble in benzene, gasoline, ether, ethanol, carbon tetrachloride, acetone, dichloroethane, insoluble in water.
Ethoxyquin may undergo a hazardous polymerization at temperatures above 320° F. 
Tends to polymerize and darken in color on exposure to light and air. 

Not compatible with oxidizing agents and with strong acids .
Ethoxyquin is a quinoline-based aromatic compound. 
Ethoxyquin is an antioxidant and serves as a feed additive with a maximum of 150mg/Kg. 

In fishmeals Ethoxyquin prevents the auto oxidation of fatty acids, i. e. effects an extension of the shelf life.
In addition to animal nutrition, ethoxyquin finds important applications in industrial settings, particularly in the rubber and plastics industries. 
Ethoxyquin is commonly added as an antioxidant additive to rubber compounds and plastics, where it inhibits the oxidative degradation caused by thermal stress and exposure to oxygen during manufacturing and throughout the product's service life. 

This antioxidant function extends the durability, elasticity, and overall performance of rubber goods such as tires, seals, and conveyor belts, thereby improving their safety and longevity. 
Furthermore, ethoxyquin is sometimes utilized in crop protection products, serving as a stabilizer to prevent premature degradation of pesticides and herbicides, which helps maintain their efficacy during storage and application.

Clear light yellow to dark brown viscous liquid discolors and stains badly. 
Quinoline insecticide, fungicide and plant growth regulator also and ingredient in other products. 
Used for preharvest or postharvest preservation of color in apples and pears. 

Ethoxyquin is used as an anti-oxidant to preserve color in paprika and ground and powdered chili. 
Ethoxyquin also is a chemical preservative used in animal feed to prevent ingredients from reacting with oxygen and becoming rancid. 
Ethoxyquin has been known to cause birth defects in pet birds and dogs

Polymerization can occur on contact with strong light and/or water. 
Keep away from oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); strong acids.
Despite its widespread usefulness, the use of ethoxyquin has been subject to regulatory scrutiny because of concerns related to its potential health effects on humans and animals. 

Some studies have suggested that prolonged or excessive exposure to ethoxyquin may cause adverse effects such as allergic reactions, liver toxicity, or accumulation of residues in animal tissues, which could have implications for food safety. 
Consequently, many countries have established maximum residue limits for ethoxyquin in food and feed products, and its usage is carefully monitored to ensure that it remains within safe thresholds. 
Ongoing research continues to evaluate the long-term safety and environmental impact of ethoxyquin, including its biodegradability and potential toxicity to aquatic life.

Uses Of Ethoxyquin:
Ethoxyquin is primarily used as a powerful antioxidant preservative to prevent the oxidation and rancidity of fats and oils in a wide range of products, which helps to maintain their freshness, nutritional quality, and shelf life over extended periods. 
One of its most common applications is in animal feed, particularly in fish meal, meat meal, and poultry by-products, where it effectively protects these ingredients from oxidative deterioration caused by exposure to air, moisture, and light during storage and transportation, ensuring that the feed remains safe and nutritious for livestock consumption. 

Beyond animal nutrition, ethoxyquin is widely employed in the rubber and plastics industries as an additive that protects materials such as tires, conveyor belts, seals, and various molded rubber goods from oxidative damage that can occur during manufacturing processes involving heat and pressure, as well as throughout the useful life of these products, thereby enhancing their durability and performance.
Ethoxyquin is an antioxidant used in the preservation of color in chili powder, ground chili, and paprika.

Antioxidant in feed and food; antidegradation agent for rubber.
Ethoxyquin is required to be added to shmeal in order to prevent it from exploding during sea transport and storage.
Ethoxyquin may be used as a plant pesticide and as an animal feed additive.

A fungicide used to control scald and other diseases, postharvest in top fruit normally used in enclosed areas.
Ethoxyquin is used as an additive to animal feed.
Ethoxyquin is used as an antioxidant for food and feed and as anti-degradation agent for rubber.

Also used as a post-harvest dip for apples and pears.
Registered in the US as an antioxidant for the control of post-harvest scald (browning) in pears.
Also registered with the FDA as a preservative for animal feed, dehydrated crops, sorghum, and for color preservation in chili powder, paprika, and ground chili.

Ethoxyquin is a quinolone-based food preservative and pesticide that is commonly used in animal feeds.
Ethoxyquin exhibits antioxidative activity and also inhibits HSP90.
Ethoxyquin is a quinoline-based antioxidant used as a food preservative and a pesticide.

Ethoxyquin is commonly used as a preservative in pet foods to prevent the rancidication of fats.
Ethoxyquin is a feed additive that is often added to shmeal.
The anti-oxidative properties prevent the contained fats from becoming "rancid" and increase safety during storage and transport.

Developed in the early 1920s, Ethoxyquin prevented tires, which were still mostly made of natural rubber, from becoming brittle due to oxidation in tire production.
Ethoxyquin is used as a preservative in some pet foods to slow the development of rancidity of fats.
Ethoxyquin is also used in some spices to prevent color loss due to oxidation of the natural carotenoid pigments.

As an antioxidant to control the browning of pears, ethoxyquin is approved in the United States and in the European Union.
In the United States, Ethoxyquin is approved for use as an animal feed additive.
Ethoxyquin is allowed in the shing industry in Norway and France as a feed stabilizer, so is commonly used in food pellets fed to farmed salmon.

Ethoxyquin is used in pellets fed to chickens on chicken farms.
Ethoxyquin is sometimes used in the agricultural sector as a stabilizing agent in pesticides and herbicides to prevent the breakdown of active ingredients, which helps maintain their effectiveness when stored or applied under varying environmental conditions. 
Ethoxyquin also finds limited use as a food preservative in some countries, where it is added in small amounts to prevent discoloration and spoilage in spices and dehydrated vegetable products, although such uses are highly regulated and subject to strict safety limits due to potential health concerns. 

Moreover, ethoxyquin is used in certain cosmetic and pharmaceutical formulations as an antioxidant to stabilize oils and other ingredients prone to degradation, thus prolonging product shelf life and maintaining efficacy.
Ethoxyquin is used to prevent spontaneous combustion of sh meal during transportation by sea.
Specic to the omega-3 industry, some krill meals and crude sh oils for animal feed are preserved using ethoxyquin.

Ethoxyquin eectively helps to reduce the risk of combustion in products such as krill or sh that are not kept frozen.
Ethoxyquin (EQ, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) is widely used in animal feed in order to protect it against lipid peroxidation.
Ethoxyquin is added to an animal feed either directly or indirectly as a component of an ingredient.

Ethoxyquin was often used as a feed additive to protect unsaturated fatty acids against oxidation.
Ethoxyquin remains stable at the high temperatures required to process dog foods during extrusion.
Ethoxyquin is important in protecting fats and oils from degrading, losing available calories, and becoming rancid.

Dog-food manufacturers have been using ethoxyquin to prevent rancidity and to maintain the nutritional quality of their products for more than 35 years.
Ethoxyquin is a synthetic antioxidant that is often added to sh meal to prevent it from exploding during transport by sea and storage.
Feed containing sh meal therefore also could contain ethoxyquin

Safety Profile Of Ethoxyquin:
Ethoxyquin, while widely used as an antioxidant and preservative, poses several hazards primarily related to its potential effects on human health and the environment, especially when exposure occurs in concentrated forms or over prolonged periods. 
Inhalation of ethoxyquin dust or aerosols may cause respiratory irritation, leading to symptoms such as coughing, sneezing, or difficulty breathing, particularly in individuals with pre-existing respiratory conditions like asthma or allergies. 

Skin contact with ethoxyquin, especially in powder or concentrated form, can result in mild to moderate irritation, redness, or dermatitis, and repeated or prolonged exposure may increase the risk of allergic skin sensitization in susceptible individuals.
Poison by intraperitoneal route moderately toxic by ingestion. 

Combustible when exposed to heat or flame; can react with oxidizing materials when heated to decomposition it emits toxic fumes of NOx.
Some speculation exists that ethoxyquin in pet foods might be responsible for multiple health problems. 
To date, the U.S. Food and Drug Administration has only found a verifiable connection between ethoxyquin and buildup of protoporphyrin IX in the liver, as well as elevations in liver-related enzymes in some animals, but no health consequences from these effects are known.

In 1997, the Center for Veterinary Medicine asked pet food manufacturers to voluntarily limit ethoxyquin levels to 75 ppm until further evidence is reported.
However, most pet foods that contain ethoxyquin have never exceeded this amount.
In 2017, reports from the Swiss Department for regional affairs laboratory, service of consummation and veterinary affairs showed that farmed salmon often exceeded the set limits for ethoxyquin contamination by several orders of magnitude and that health effects of the chemical on the human body were not studied in sufficient detail.

In 2013, researchers at the Department of General Genetics, Molecular Biology and Plant Biotechnology, Faculty of Biology and Environmental Protection, University of Łódź, Poland, summarized the health effects of animals and humans exposed to varying levels of ethoxyquin observed in scientific studies. 
The summary includes: loss of weight, changes in liver, kidney, alimentary duct, urinary bladder and mitochondria, anemia, lethargy, discolored urine, skin, or fur, increase in mortality, detrimental effect on immunity, condition factor of final body weight in relation to body length of fish and inducement of allergies (contact exposure).