This paper presents data in a manner that is more like a summary rather than a complex risk assessment process of Total Petroleum Hydrocarbons (TPH). This is indeed, a wide family of compounds, hence limiting the scope of the paper to undertake inclusive environmental, physical/chemical, and even health data on each and every hydrocarbon. Therefore, the paper acts as a guideline to understanding TPH, what is known about it, the probability of considerable exposure, and possibility of health repercussions.
Uses and Limitations of Risk Assessment Involving Total Petroleum Hydrocarbon Introduction TPH is the measurable quantity of petroleum-oriented hydrocarbon in an environmental medium. Thus, it depends entirely on analysis of the media in which it is located (Gustafson, 2002). Since this is a measured quantity without identifying its components, the value of TPH remains a mixture. Thus, on its own it is not a reliable indicator of dangers to human beings or to the environment. The value of TPH can be as an aftermath from the various analytical methods.
The analytical methods have been in use for decades now. Analytical methods keep on evolving to cater for ever changing need of assessing the risk involved in the day to day utilization of TPH. In response to these key developments, the definition of TPH is closely linked to analytical methods and their values. There are several hundred individual hydrocarbon chemicals defined as petroleum-based, with more than 2. 50 petroleum components (Wharfe et al, 2007, p. 268). Further, each petroleum product has its own mix of constituents.
This is because crude oil, itself has varying components. Some of this variation is reflected in the finished petroleum product. The acronym for petroleum hydrocarbons (PHC) is broadly used to refer to the hydrogen- and carbon-containing compounds originating from crude oil, but PHC should be distinguished from TPH, because TPH is specifically linked to environmental sampling and analytical results. Petroleum crude oil can be largely divided into asphaltic, mixed crude oil and paraffinic (Wharfe et al, 2007, p. 268-9).
Overview of TPH Paraffinic crude oils are composed of aliphatic hydrocarbons (paraffin), paraffin wax (long chain aliphatic), and high level oils. Naphtha is the lightest of the paraffin fraction, followed by kerosene fraction. Asphaltic crude oil contains larger concentration of cycloaliphatic and high viscosity lubricating oil. Petroleum solvents are the product of crude oil distillation and are generally classified by boiling point ranges. Lubricants, waxes, and greases are high boiling point fraction of crude oil.
The heaviest, solid fractions of crude oils are the residuals or bitumen. Some hydrocarbons are highly predictable like jet fuels which constitute specific percentages of defined component; others, like automotive gasoline, contain broader ranges of hydrocarbon kinds and amounts (see table 1), which provides a comprehensive list of petroleum hydrocarbons (Tannenbaum, 2007, p. 473). Petroleum products, themselves, are the source of the many components, but do not define what TPH is.
They help define the potential hydrocarbons that become environmental contaminants, but any ultimate exposure is determined also by how the product changes with use, by the nature of the release, and by the hydrocarbon’s environmental fate. When hydrocarbons are released into the soil, water, and or air, changes occur that considerably determine their probable impacts. Biological, chemical, and Physical processes change the concentration and location of hydrocarbons at any specific site (Tannenbaum, 2007, p. 475).
Petroleum hydrocarbons are commonly found environmental contaminants, though they are not usually classified as hazardous waste. Many petroleum products are used in modern society, including those that are fundamental to human life (that is, fuels used in transport industry, heating and power-generating fuel). The volume of crude oil or petroleum products that is used today sideline all other chemicals of environmental and health concern. Due to the number of facilities, individuals, and processes and the various ways the products are handled and stored, environmental contamination is a potential threat to human life (Gustafson, 2002).