Definition

• Adipocere (Latin adipo: fat, cire: wax) is formation of an offensive, rancid smelling, soft, whitish or grayish white, crumbly, waxy and greasy material (similar to soap) occurring in fatty tissues of a dead body subjected to moisture.
• Factors favorable to adipocere formation include mildly alkaline pH, warm temperature, anaerobic conditions, and moisture. Cold temperature, lime, and aerobic conditions are limiting factors.

Mechanism of formation

• Adipocere consists mainly of fatty acids formed due to postmortem hydrolysis and hydrogenation of body fats. The process needs water which is provided by the body fluid of soft tissues.
• The chemical reaction essentially involves conversion of unsaturated liquid fats (oleic acid) to saturated solid higher fatty acids, like palmitic, stearic and hydro-xystearic acid, mostly palmitic acid

Time required for formation

• In hot and moist environment, it may occur by the end of 1 week (earliest recorded—3 days).
• In temperate countries, it starts in 3 weeks and completes in about 3 months.

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Distribution

• It forms at any site where fatty tissue is present. The face, buttocks, breasts and abdomen are the usual sites.
• In case of a female body, this change will be seen almost all over the body due to presence of a good amount of subcutaneous fat. Internally, small muscles are dehydrated and become very thin, and have a uniform grayish color.
• The depths of large muscles have a pink/red color with complete conversion of the fat to adipocere.

Factors Influencing Adipocere Formation�

• Age: Fetuses < 7 months do not show adipocere formation.
• Built: In obese people and mature newborn, it is formed quickly.
• Environmental temperature: Heat accelerates and cold retards adipocere formation in a body.
• Moisture: Moisture is essential for chemical reactions to occur. It occurs rapidly in bodies submerged in water than in damp soil.
• Air current: It retards adipocere formation by evaporation of the body fluid and by reducing the body temperature.
• Running water: Adipocere formation is retarded as the electrolytes are washed away from the surface of the body which is necessary for the change.
• Bacterial infection: Early activity by anerobes such as Clostridium perfringens assist in the reaction, as the bacteria produce lecithinase which facilitates hydrolysis and hydrogenation.
• A warm, moist and anaerobic environment thus favors adipocere formation.

Medico-legal Importance�

• Sign of death: It is the surest sign of death.
• Time since death: It gives a rough estimate about the time since death.
• Personal identification: When the process involves the face, the features are well-preserved which help in identification.
• Recognition of injuries: The cause of death may be determined, since injuries can be recognized.
• Place of disposable of body: Some idea about the place of disposal of the body can be made, since its formation requires a warm place with high humidity or presence of moisture or water.