Introduction to military and civilian standards related to anti-icing agents for aviation fuel systems in the United States
The production, testing and use of aviation fuel system anti-icing agents (FSII) need to follow a series of standards to ensure their quality, safety and effectiveness. Due to the wide application of FSII in the military field, U.S. military standards and civilian standards formulated by organizations such as ASTM are widely adopted, and countries and organizations such as the United Kingdom and NATO have formulated corresponding standards (see attached table). Among them, the U.S. military and civil aviation agencies and enterprises mainly refer to ASTM D4171, MIL-DTL-27686, MIL-DTL-85470 and other standards. The scope of application and main content of these standards are introduced below:
01 ASTM D4171-22 "Standard Specification for Anti-icing Agents in Fuel Systems"
This standard is mainly used for two anti-icing agents in aviation fuel systems, Type II (isopropyl alcohol) and Type III (diethylene glycol monomethyl ether); it defines in detail the physical and chemical performance indicators of the two anti-icing agents, such as flash points, water content, ethylene glycol content, etc.; it is required that the anti-icing agent must be uniform, clear, bright, and free of suspended matter and foreign matter, and the addition of specific antioxidants is allowed. The standard also provides detailed test methods and referenced ASTM and other standards.
02 MIL-DTL-27686G "Detailed Specification for Anti-icing Agents in Fuel Systems"
This standard is mainly used for ethylene glycol monomethyl ether (EGME) aviation fuel system anti-icing agent. It is particularly emphasized that this anti-icing agent is only for military use and is a special product for military weapon systems. The standard defines various physical and chemical performance indicators of anti-icing agents in detail, such as distillation range, specific gravity, refractive index, water content, etc., and allows the addition of specific antioxidants. The standard provides detailed test methods and referenced documents and standards. The standard also emphasizes the toxicity and flammability of ethylene glycol monomethyl ether and lists corresponding safety precautions.
03 MIL-DTL-85470B "Detailed Specification for Fuel System Anti-Ice Agents, High Flash Point"
This standard is mainly used for diethylene glycol monomethyl ether (DiEGME) aviation fuel system anti-icing agent. The standard defines various physical and chemical performance indicators of anti-icing agents in detail, such as flash point, water content, ethylene glycol content, etc., allows the addition of specific antioxidants, and requires that anti-icing agents must be uniform, clear, bright, and free of suspended solids and foreign body. The standard provides detailed test methods and referenced documents and standards. The standard specifically emphasizes that this anti-icing agent is only used in aviation turbine engine fuel.
04 ASTM D910-21 "Standard Specification for Aviation Gasoline"
The standard defines various performance indicators of three grades of leaded aviation gasoline (100, 100LL and 100VLL), including combustion performance, components, volatility, corrosiveness, pollutants, etc., and gives specific indicator limits and Types and maximum concentrations of additives allowed. This standard allows the use of isopropyl alcohol (IPA) as a fuel system anti-icing agent for aviation gasoline, and the isopropyl alcohol used must comply with the requirements of Type II fuel system anti-icing agent in ASTM D4171. The specific concentration used is required to comply with the aircraft manufacturing businessman's suggestions. Its appendix states that the use of isopropyl alcohol as an anti-icing agent may result in a decrease in the antiknock properties of gasoline.
05 ASTM D1655-19a "Standard Specification for Aviation Turbine Fuel"
This standard is primarily used for aviation turbine fuels (Jet A and Jet A-1) and allows the use of diethylene glycol monomethyl ether (DiEGME) as a fuel system anti-icing agent. Appendix 2 lists the dosage range of DiEGME: by volume, the minimum value is 0.07% and the maximum value is 0.15%. Additionally, the standard states that if additives are diluted, refined hydrocarbons or reagent grade hydrocarbons that comply with D1655 must be used.
06 ASTM D5006-11 "Standard Test Method for Measuring Ether Anti-Icing Agents in Aviation Fuels"
This standard is a test method primarily used to measure the concentration of diethylene glycol monomethyl ether (DiEGME) in aviation fuel. Neither the selection of FSII type nor the dose of FSII is specified. The standard provides detailed steps for determining DiEGME concentration, including water extraction and measurement using a refractometer, as well as information on instrument calibration, reagents and sample handling.
07 MIL-DTL-5624W "Detailed Specification for Aviation Turbine Fuels, JP-4 and JP-5"
The standard states that fuel system anti-icing agents (DiEGME) that meet MIL-DTL-85470 standards can be used. The standard does not directly provide dosage requirements, but requires the time and method of addition, that is, the addition should be after the refining process is completed and before the fuel contacts the atmosphere. In addition, the standard also stipulates that additives must be approved by the authorized agency and indicates that the location of the additive must be specified in the procurement document.
08 MIL-DTL-83133J "Detailed Specification for Aviation Kerosene Type Turbine Fuel, JP-8, NATO F-35 and JP-8+100"
The standard states that for JP-8 (NATO F-34) fuel, fuel system anti-icing agents that comply with the MIL-DTL-85470 standard must be used; for NATO F-35 fuel, the use of anti-icing agents is not mandatory unless specifically required by the purchaser. Ice agent; for JP-8+100 (NATO F-37), the addition of anti-icing agent is not mandatory. The standard does not directly specify dosage, but requires compliance with MIL-DTL-85470. In addition, the standard also stipulates the order and time of adding additives in JP-8 fuel, and indicates that the location of anti-icing agent addition shall be determined through negotiation between the purchaser and the supplier.
Tips: The US military’s classification of anti-icing agents for aviation fuel systems
➤ Type I (EGME): Refers to ethylene glycol monomethyl ether, an early anti-icing agent that is now considered inferior to other alternatives. It was once listed in ASTM D4171, but was subsequently deleted.
➤ Type II (IPA): refers to isopropyl alcohol, which was once used as an anti-icing agent for aviation gasoline.
➤ Type III (DiEGME): refers to diethylene glycol monomethyl ether, which is currently a commonly used anti-icing agent for aviation turbine fuel and is listed as the main specification object in most new versions of standards.
Attached table: List of FSII industry related standards
Classification |
Standard grade |
Standard English name |
NATO code |
ASTM |
ASTM D4171-22 |
Standard Specification for Fuel System Icing Inhibitors |
- |
ASTM |
ASTM D910 |
Standard Specification for Aviation Gasolines |
- |
ASTM |
ASTM-D1655-19a |
Standard Specification for Aviation Turbine Fuels |
- |
ASTM |
ASTM-D5006-11 (2021) |
Standard Test Method for Measurement of Fuel System Icing Inhibitors (Ether Type) in Aviation Fuels |
- |
U.S. Military Standard |
MIL-DTL-85470B |
Inhibitor, Icing, Fuel System, High Flash |
S-1745 |
U.S. Military Standard |
MIL-DTL-27686G |
Detail Specification Inhibitor, Icing, Fuel System |
S-748 |
U.S. Military Standard |
MIL-DTL-83133J |
Detail Specification Turbine Fuel, Aviation, Kerosene Type, JP-8 (NATO F-34), NATO F-35, and JP-8+100 (NATO F-37) |
F-34, F-35, F-37 |
U.S. Military Standard |
MIL-DTL-5624W |
Detail Specification Turbine Fuel, Aviation, Grades JP-4 and JP-5 |
F-40, F-44 |
british military standard |
DEF STAN 68-252 |
Fuel System Icing Inhibitor |
S-1745 |
british military standard |
DEF STAN 91-86 |
Turbine Fuel, Aviation Kerosine Type: High Flash Type, Containing Fuel System Icing Inhibitor |
F-44 |
british military standard |
DEF STAN 91-87 |
Turbine Fuel, Aviation Kerosine Type, Containing Fuel System Icing Inhibitor |
F-34 |
british military standard |
DEF STAN 91-88 |
Turbine Fuel, Aviation: Wide Cut Type, Containing Fuel System Icing Inhibitor |
F-40 |
british military standard |
DEF STAN 91-91 |
Turbine Fuel, Kerosene Type, Jet A-1; |
F-35 |
Further reading
What is aviation fuel system anti-icing agent?
Aviation fuel system anti-icing agent (also known as Fuel System Icing Inhibitor, FSII) is an additive specifically designed to prevent the formation of ice crystals in aviation fuel at high altitudes and/or low temperatures. Although water has been removed as much as possible during fuel production, handling and use, small amounts of free water may still be present in the fuel for a variety of reasons. At low temperatures, this moisture will crystallize and may cause clogging of fuel filters, fuel pump screens, fuel lines, and other fuel system components, causing problems such as loss of power, engine backfiring, and even stalling. The characteristic of FSII is that it is weakly soluble in fuel, but more easily soluble in water. Therefore, when a small amount of free water in the fuel absorbs FSII, the freezing point will be significantly lowered, thereby preventing the formation of ice crystals and ensuring the reliability of the fuel in cold environments. sex and safety.
From a chemical point of view, early FSII mostly used ethylene glycol monomethyl ether (EGME), that is, 2-methoxyethanol, with the molecular formula C3H8O2; since 1994, EGME with a higher flash point and lower hazard has also been used. Diethylene glycol monomethyl ether (DiEGME), that is, 2-(2-methoxyethoxy)ethanol (DiEGME), has a molecular formula of C6H14O3, and the latter is currently more widely used. EGME is certified as a pesticide by the U.S. Environmental Protection Agency (EPA), and DiEGME does not have official pesticide certification. DiEGME is a strong solvent and high concentrations may damage fuel tanks and filters; therefore, it is recommended to avoid long-term storage of FSII-fuel mixtures.
FSII can be used in civil and military aviation. However, in most large commercial aircraft and newer general aviation business aircraft, fuel heating components, such as electric fuel heaters, fuel system/lubricating oil system heat exchangers, or fuel system/hydraulic system heat exchangers, have been added to provide larger Minimize ice crystal formation. However, many older commercial and business aircraft, small general aviation aircraft, and military aircraft are often not equipped with such fuel temperature-increasing components due to cost and/or weight constraints, making FSII a necessary additive in the fuel specifications for these aircraft. For commercial grade fuel, it is up to the discretion of the airline whether to add FSII.
The major global fuel system anti-icing agent (FSII) manufacturers are: Innospec, Prist®, D Ice®, Afton Chemical Corporation, Chevron Oronite and Eastman Chemical Company of the United States; BASF Group (BASF) of Germany, Advance Petrochemicals of India, and Aero-Sense from Belgium. Among them, Prist® and D Ice® are well-known brands on the market, known for their effectiveness in preventing the formation of ice crystals under low temperature conditions. Testing equipment manufacturer: Gammon Tech Product, etc. The well-known product is Anti-Ice HB-PC B/2, which is used to detect the concentration of anti-icing agent in fuel. Filling equipment manufacturers: Quanah Corp, PRIST, etc. The well-known product is the PRB-101 proportional mixer.