ASTM D7719 Standard Specification for High Aromatic Content Unleaded Hydrocarbon Aviation Gasoline
4. General
4.1 This specification, unless otherwise provided, prescribes the required properties of a high aromatic content unleaded hydrocarbon aviation gasoline at the time and place of delivery.

5. Classification
5.1 One grade of high aromatic content unleaded hydrocarbon aviation gasoline is provided, known as UL102.

6. Materials and Manufacture
6.1 D7719 fuel, except as otherwise specified in this specification, shall consist of blends of refined hydrocarbons. The sources for these hydrocarbons include biomass, natural gas, or crude petroleum.
6.1.1 See Appendix X1 for one particular composition that meets the parameters of Table 1.

6.2 Additives - These can be added to each grade of D7719 fuel in the amount, and of the composition, specified in the following list of approved materials:
6.2.1 Dyes - The total maximum concentration of dye in the fuel is 6.0 mg/L. (See X1.1.1 and X2.2.7.)
6.2.1.1 The only blue dye present in the finished fuel shall be essentially 1,4-dialkylaminoanthraquinone.

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

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

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

6.2.2 Other Additives - These may be added 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.
6.2.2.1 Antioxidants - The following oxidation inhibitors may be added to the fuel separately, or in combination, in total concentration not to exceed 12 mg of inhibitor (not including weight of solvent) per litre of fuel.
(1) 2,6-ditertiary butyl-4-methylphenol.
(2) 2,4-dimethyl-6-tertiary butylphenol.
(3) 2,6-ditertiary butylphenol.
(4) 75 % minimum 2,6-ditertiary butylphenol plus 25 % maximum mixed tertiary and tritertiary butylphenols.
(5) 75 % minimum di- and tri-isopropyl phenols plus 25 % maximum di- and tri-tertiary butylphenols.
(6) 72 % minimum 2,4-dimethyl-6-tertiary butylphenol plus 28 % maximum monomethyl and dimethyl tertiary butylphenols.
(7) N,N' -di-isopropyl-para-phenylenediamine.
(8) N,N’-di-secondary-butyl-para-phenylenediamine.

6.2.2.2 Fuel System Icing Inhibitor (FSII) - One of the following materials may be used:
(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.
(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.
(3) Test Method D5006 can be used to determine the concentration of Di-EGME in aviation fuels.

NOTE 1 - Addition of isopropyl alcohol (IPA) may reduce knock ratings below minimum specification values. See X2.2.3.

6.2.2.3 Electrical Conductivity Additive - Stadis 450 in concentrations up to 3 mg/L is permitted. When loss of fuel conductivity necessitates retreatment with electrical conductivity additive, further addition is permissible

6.2.2.4 Corrosion Inhibitor Additive - The following corrosion inhibitors may be added to the fuel in concentrations not to exceed the maximum allowable concentration (MAC) listed for each additive.
DCI-4A MAC = 24.0 g/m3
DCI-6A MAC = 15.0 g/m3
HITEC 580 MAC = 22.5 g/m3
NALCO 5403 MAC = 22.5 g/m3
NALCO 5405 MAC = 11.0 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

7. Detailed Requirements
7.1 The D7719 fuel shall conform to the requirements prescribed in Table 1.

7.2 Test results shall not exceed the maximum or be less than the minimum values specified in Table 1. No allowance shall be made for the precision of the test methods. To determine the conformance to the specification requirement, a test result may be rounded to the same number of significant figures as in Table 1 using Practice E29. Where multiple determinations are made, the average result, rounded according to Practice E29, shall be used.

8. Workmanship, Finish, and Appearance
8.1 The D7719 fuel specified in this specification shall be free from undissolved water, sediment, and suspended matter. No substances of known dangerous toxicity, under usual conditions of handling and use, shall be present except as permitted in this specification.

9. Sampling
9.1 Because of the importance of proper sampling procedures in establishing fuel quality, use the appropriate procedures in Practice D4057 or Practice D4177.
9.1.1 Although automatic sampling following Practice D4177 may be useful in certain situations, initial manufacturer/supplier specification compliance testing shall be performed on a sample taken following procedures in Practice D4057.

9.2 A number of D7719 fuel properties, including copper corrosion, electrical conductivity, and others are very sensitive to trace contamination which can originate from sample containers. For recommended sample containers, refer to Practice D4306.