Environmental Impact

The Environmental Impact

The livestock and poultry industries of North America use state-of-the-art technology in genetics, feeding, husbandry and production practices, contributing to the continued substantial growth and efficiency of these industries. This translates into a per capita meat consumption that is among the highest in the world thanks to its abundance, relative cost, safety and recognized quality.

The North American rendering industry renders and recycles approximately 59 billion pounds of inedible animal by-products annually. The by-products’ sources vary from livestock and poultry carcasses plus offal, spent cooking fats and oils, fat trimmings, bones, other meat and poultry processed material considered unwholesome from slaughter and processing facilities, and waste material from supermarkets and restaurants.

This diversity of inedible animal by-products accounts for approximately 9 billion pounds of reclaimed animal fat annually. The use of rendered fat is a concentrated source of energy for animal and poultry feeds. Undoubtedly, the rendering process provides the most logical and environmentally acceptable approach for recycling animals and inedible material into usable commodities.

Physical, Chemical and Toxicological Properties

This section profiles the inter-relationship of factors that contribute to the production of animal fats and oils, reviews the basic physical, chemical and toxicological properties, and compares the major differences to petroleum oils. It provides pertinent information on the environmental attributes of animal fats and oils and clarifies the safety perspective in contrast to petroleum oils.

The physical properties of fats and oils are of importance to accommodate their uses in applicable products and depend on the oiliness, solubility, surface activity, melting behavior, or other characteristics peculiar to long-chain compounds. The properties associated with solid-liquid and liquid-solid, or the process of melting and solidification are prime examples. In actuality, the use of the term fats and oils are related to these changes, and need further elucidation. At standard temperatures, the fat connotation refers to a material that is solid, and oil a liquid material. The reality is a fat is seldom ever completely solid e.g. tallow and lard, and is nothing more than intermixtures of a liquid phase with a solid phase.

Even though they are made up of the same or similar fatty acids, natural fats and oils vary widely in their physical properties for two major reasons: (a) individual fats and oils vary over relatively large ranges in the proportions of the component fatty acids, and (b) the structures of the individual component triglycerides vary.

Many factors have a direct influence on the fatty acids composition as well as the triglyceride structure of natural fats and oils in animal species. The most significant conditions contributing to the variables are: (1) the diet of the animal; (2) the location of the fat in the animal e.g. milk fat differs from depot fat; (3) there are large differences in the composition of fat in different animal species e.g. pork, beef and lamb fats; (4) the health status of the animal and the environment in which the animal is raised also causes composition variables.

Fats and oils possess chemical structures that are compatible with the cells of all living organisms and are thus easily utilized by them as a source of food for maintenance, growth and other life functions. Toxicology evaluations have shown that animal fats and oils did not prove toxic to aquatic life at concentrations up to 10,000 PPM. Adjunctly, fats and oils showed no comparative toxicity to fish at the limit of their solubility in water, or to humans and animals either directly or through the accumulation in the food supply. There are also no accumulating or otherwise hazardous components in animal fats that are irritating, toxic or carcinogenic.

Animal fats and oils are easily biodegraded by bacteria using them as food. Additionally, animal fats do not exhibit any characteristics commonly considered hazardous (i.e. flammable, combustible, corrosive, explosive or radioactive). They do not cause significant harm when spilled, and have been designated Generally Recognized As Safe (GRAS) status by the Food and Drug Administration (FDA).

These basic qualities of animal fats and oils differ substantially from petroleum oils that produce toxicity to aquatic life at water concentrations in the low “parts-per-million” range. One of the other potentially serious health concerns associated with petroleum oil spills is the accumulation of polycyclic aromatic hydrocarbons (several of which are carcinogens) in fish tissues.

Other components of petroleum oils at certain exposures cause skin and eye irritations, nervous system disorders, and carcinogenicity. These health related concerns are reflected in EPA’s maximum tolerances in drinking water, which range from 0.005 to 2.0 PPM.

Petroleum spills contribute to fouling of plumage in birds with secondary loss of bouyancy and insulating capacity, accompanied by significant toxicity. In essence, petroleum oils in general pose substantially greater risks to human and animal health than do animal fats and oils.