As a Petroleum Laboratory NCO, you will be responsible for reviewing laboratory test results. One of the
items you must check for is product deterioration. Your ability to accurately identify product deterioration
may affect the outcome of the sending unit's mission.
PART A - IDENTIFY TYPES OF DETERIORATION
Weathering: the loss of light ends. Weathering is detected by the distillation and the Reid Vapor
Pressure (RVP) tests.
Oxidation: gum formation. Oxidation is detected by the existent gum, potential gum, and oxidation
Loss of additives: detected by the foam, cloud/pour, lead, and color tests.
PART B - CAUSES OF DETERIORATION
The following conditions contribute to weathering:
Open gauge or sampling hatches from which the vapors escape.
Ineffective vapor systems.
Above ground tanks painted dark; heat absorbing colors instead of light colors.
Use of above ground tanks instead of underground tanks for JP-4, MOGAS, or AVGAS.
Poor stock rotation procedures.
The following conditions contribute to oxidation:
Excessive exposure of fuel to oxygen through open hatches.
Excessive heat from dark painted, heat absorbing tanks.
Long term storage with poor stock procedures.
The following conditions contribute to loss of additives:
Excessive heat contact.
Presence of water bottoms that cannot be moved.
Use of uncoated storage tanks.
PART C - METHODS OF DETECTING PRODUCT DETERIORATION
The most efficient method used to detect deterioration is the use of a good quality surveillance program with
scheduled laboratory testing of all stored products. Changes in product color can be the first indication of
deterioration; however, the extent of product deterioration can be determined only through laboratory
analysis. Among laboratory tests which are helpful in determining product deterioration are the following.
Color. A visual change in product color, either gradual or abrupt, is usually the first indication of product
deterioration. This observation should be compared with other, more detailed tests. Usually, a gradual
change indicates deterioration whereas an abrupt change indicates contamination.
Appearance. The visual workmanship of a product can show sediment, fibers, or a haze caused by
entrained water. These are indicators of contamination; however, a haze could also imply loss of additives
Reid Vapor Pressure (RVP). This test is an excellent indication that a product has deteriorated. If the
RVP is low and the gum is oily, this indicates contamination. If the RVP is low and the gum is dry, this
indicates deterioration. If the RVP is high, this indicates contamination, only.
Existent Gum. The presence of high levels of dry gum indicates that oxidation has taken place. Oily
gum shows contamination by a heavier product.