ASTM D910 standard specification for aviation gasolines
6. Materials and Manufacture
6.1 Aviation gasoline, except as otherwise specified in this specification, shall consist of blends of refined hydrocarbons derived from crude petroleum, natural gasoline, or blends, thereof, with synthetic hydrocarbons or aromatic hydrocarbons, or both.

6.2 Additives - Mandatory, shall be added to each grade of aviation gasoline in the amount and of the composition specified in the following list of approved materials.

6.2.1 Tetraethyl Lead, shall be added in the form of an antiknock mixture containing not less than 61 mass % of tetraethyl lead and sufficient ethylene dibromide to provide two bromine atoms per atom of lead. The balance shall contain no added ingredients other than kerosine, an approved oxidation inhibitor, and blue dye, as specified herein. The maximum concentration limit for each grade of gasoline is specified in Table 1.

6.2.1.1 If mutually agreed upon by the fuel producer and additive vendor, tetraethyl lead antiknock mixture may be diluted with 20 mass % of a mixed aromatic solvent having a minimum flash point of 60°C according to Test Methods D93 when the product is to be handled in cold climates. The TEL content of the dilute product is reduced to 49 mass %, so that the amount of antiknock additive must be adjusted to achieve the necessary lead level. The dilute product still delivers two bromine atoms per atom of lead.

6.2.2 Dyes - The maximum concentration limits in each grade of gasoline are specified in Table 1.

6.2.2.1 The only blue dye that shall be present in the finished gasoline shall be essentially 1,4-dialkylaminoanthraquinone.

6.2.2.2 The only yellow dyes that shall be present in the finished gasoline shall be essentially p-diethylaminoazobenzene (Color Index No. 11021) or 1,3-benzenediol 2,4-bis [(alkylphenyl)azo-].

6.2.2.3 The only red dye that shall be present in the finished gasoline shall be essentially alkyl derivatives of azobenzene-4-azo-2-naphthol.

6.2.2.4 The only orange dye that shall be present in the finished gasoline shall be essentially benzene-azo-2-napthol (Color Index No. 12055).

6.3 Additives - These may be added to each grade of aviation gasoline in the amount and of the composition specified in the following list of approved materials. The quantities and types shall be declared by the manufacturer. Additives added after the point of manufacture shall also be declared.

6.3.1 Antioxidants - The following oxidation inhibitors may be added to the gasoline separately, or in combination, in total concentration not to exceed 12 mg of inhibitor (not including weight of solvent) per litre of fuel.

6.3.1.1 2,6-ditertiary butyl-4-methylphenol.

6.3.1.2 2,4-dimethyl-6-tertiary butylphenol.

6.3.1.3 2,6-ditertiary butylphenol.

6.3.1.4 75 % minimum 2,6-ditertiary butylphenol plus 25 % maximum mixed tertiary and tritertiary butylphenols.

6.3.1.5 75 % minimum di- and tri-isopropyl phenols plus 25 % maximum di- and tri-tertiary butylphenols.

6.3.1.6 72 % minimum 2,4-dimethyl-6-tertiary butylphenol plus 28 % maximum monomethyl and dimethyl tertiary butylphenols.

6.3.1.7 N,N8-di-isopropyl-para-phenylenediamine.

6.3.1.8 N,N8-di-secondary-butyl-para-phenylenediamine.

6.3.2 Fuel System Icing Inhibitor (FSII) - One of the following may be used.

6.3.2.1 Isopropyl Alcohol (IPA, propan-2-ol), in accordance with the requirements of Specification D4171 (Type II). May be used in concentrations recommended by the aircraft manufacturer when required by the aircraft owner/operator.

NOTE 3 - Addition of isopropyl alcohol (IPA) may reduce knock ratings below minimum specification values (see X1.2.4).

6.3.2.2 Di-Ethylene Glycol Monomethyl Ether (Di-EGME), conforming to the requirements of Specification D4171 (Type III). May be used in concentrations of 0.10 to 0.15 volume % when required by the aircraft owner/operator.

6.3.2.3 Test Method D5006 can be used to determine the concentration of Di-EGME in aviation fuels.

6.3.3 Electrical Conductivity Additive - Stadis 4507 in concentrations up to 3 mg/L is permitted. When loss of fuel conductivity necessitates retreatment with electrical conductivity additive, further addition is permissible up to a maximum cumulative level of 5 mg/L of Stadis 450.

6.3.4 Corrosion Inhibitor Additive - The following corrosion inhibitors may be added to the gasoline in concentrations not to exceed the maximum allowable concentration (MAC) listed for each additive.
DCI-4A MAC = 22.5 g/m3
DCI-6A MAC = 9.0 g/m3
HITEC 580 MAC = 22.5 g/m3
NALCO 5403 MAC = 22.5 g/m3
NALCO 5405 MAC = 11.0 g/m3
PRI-19 MAC = 22.5 g/m3
UNICOR J MAC = 22.5 g/m3
SPEC-AID 8Q22 MAC = 24.0 g/m3
TOLAD 351 MAC = 24.0 g/m3
TOLAD 4410 MAC = 22.5 g/m3