Facts And Myths About Petroleum Distillates
by Dean Whitehead (Read Biography Below)
A great deal of misinformation is circulating among the general public with regards to automotive appearance products. In particular, I would like to take time to try and shed some light on the ambiguous and confusing use of the term “petroleum distillates”.
Recently, I have heard and read comments and excerpts from “seminars”, web site forums and product advertisements concerning petroleum distillates that misleads or misinforms the consumer. Anyone who makes the blanket statement that all products containing petroleum distillates are harmful to car finishes, fiberglass or plastics has no real knowledge of science or petroleum refining. False information is used to scare consumers and take advantage of their lack of technical knowledge in order to sell what may be an inferior product. This is unfortunate and reflects the seamier side of advertising and negative marketing.
WHAT ARE PETROLEUM DISTILLATES?
Some people are mystified by the name itself “petroleum distillates”, but that is exactly what they are — products made from crude oil that have been distilled in a refinery and then usually processed further and purified in some manner. The word petroleum, derived from the Latin petra and oleum, literally means “rock oil” and refers to hydrocarbons that occur in sedimentary rocks of the Earth's crust. Because most people mistakenly believe that all petroleum distillates must be similar, they find it hard to believe that there are so many totally different types, many with completely opposite characteristics and uses. In fact, even the term “distillate” raises concerns in some minds. Yet, lots of common and very beneficial things such as water are distilled to remove impurities. The list is long but the point is that distillation is neither good nor bad, just a tool to make something more useful.
THE DISTILLATION PROCESS
Distillation is still the basic process used to separate and purify the components of crude oil. The type and source of the crude oil heavily influences the resulting by-products. Crude oil is a complex mixture of hydrocarbons with impurities like sulfur, nitrogen and small amounts of metal. It is found throughout the world and varies greatly in content and composition. There are thousands of types, varying from a nearly clear liquid with the consistency of kerosene, to a solid (at room temperature) that looks like brown candle wax and, of course, the heavy black tarry kind that is usually what the general public visualizes when thinking of crude oil.
The primary function of an oil refinery is distillation — i.e., the crude oil is heated in a large closed vessel (usually called a still). The lighter components boil off first and rise to a higher point inside a tower above the still. The heavier components boil off at higher temperatures and condense back into liquids more quickly. These products are captured on trays at each level and pass out of the tower. The lighter and more volatile products are used in gasoline or as solvents, the next heavier might be used as diesel or stove oil and the next as lubricants, and so forth. Frequently, the leftover crude is then subjected to more processing (typically catalytic and thermal cracking) in which many more compounds are formed and then separated again by distillation. The amount of product distilled from crude is dependent on its characteristics. Some crudes will yield over 90% distillates while others may yield much less.
RESULTS OF DISTILLATION
The nice thing about petroleum distillate is that the distillation process leaves behind most of the nonvolatile (like asphalt). As you may know, gasoline is a typical petroleum distillate as are kerosene and mineral spirits. Yet, so are motor oil, cutting oils and the base oil used in many types of grease.
The distillates usually contain three general classes of compounds, aromatic, naphthenic and paraffinic hydrocarbons.
• Aromatics are great solvents and a base for many types of useful compounds. They are a perfect ingredient for making such things as carburetor cleaner or a paint remover where strong solvency is needed.
• Naphthenics (AKA cycloparaffins) are used to make light oils, solvents and even as a base for things like detergents and paint dryers.
• Paraffinic compounds have much less solvency and many are purified further. They are used in a myriad of consumer products, such as ingredients in many lotions and skin creams. Crystal clear white oils are used as a laxative, to coat pans in bakeries and as a base for medicines. Paraffinic compounds are perfect for use as a component in automotive waxes and polishes and those products used to treat painted surfaces, vinyl and plastic for reasons to be discussed later.
All of these products started as a distillate of petroleum but ended up being as different as night and day. This is because petroleum distillates can be further purified, re-distilled, reacted and combined with various other chemicals to produce a wide range of useful products.
PRODUCT LABELING REQUIREMENTS
The Consumer Product Safety Commission (a government agency) requires any product that contains lighter petroleum distillates in its formula to be labeled with a warning that it “contains petroleum distillates”. The warning is provided to help doctors and emergency medical personnel understand how best to treat children or others who might accidentally drink the product. Child safety is a common concern when storing any of the thousands of products that may be found in your garage, laundry room, or under your kitchen sink. In the event someone ingests a product containing petroleum distillates, medical personnel may elect not to induce vomiting.
BENEFICIAL RESULTS FOR APPEARANCE
The reason that petroleum distillates are used in many appearance care products is because they perform many different and important functions at an affordable price. About 90% of the thousands of Car Waxes and Polishes formulated today contain significant amounts of petroleum distillate, from the best known brands to the lesser known, as well as the highly regarded premium quality brands used by professional detailers. It is used in these products because petroleum distillates easily dissolve waxes and silicones and become an excellent medium to allow them to be spread on a surface. They also cut quickly through oily dirt and light grease and help lubricate the surface and prevent scratching.
Products that are used on plastic, vinyl and rubber surfaces should be formulated from very special grades of petroleum distillate that contain little if any aromatic and naphthenic molecules. While this type of highly refined paraffinic distillate costs a good deal more, it helps insure that the product does not attack the surface or remove important components from the vinyl or rubber when used as directed — yet, it does help to clean and lubricate the surface. Such products can be formulated to leave behind a rich and protective film of wax or silicone (or both) to help lengthen the surface’s useful life and prevent cracking and shrinkage. The use of petroleum distillate also allows premium UV Blockers to be included in the formulation as the most effective ones are not soluble in water. This can provide excellent protection against the surface deterioration, chalking and fading caused by sunlight.
A COMMON SENSE DECISION
Summing it all up, there are a large number of products available today that contain petroleum distillates. The mere fact that they contain petroleum distillates doesn’t tell you much about the product’s quality. In spite of spending 40 years formulating specialty products, without the complete formula I can’t determine product quality. I do know that many formulators do their homework in product development, performance and quality control. However, I am suspicious of companies and products that rely on negative advertising, rather than selling their product on its own merits. Therefore, I rely on a manufacturer’s reputation and especially on recommendations from other users when judging what product to buy for the first time and then by my own experience after I’ve used it for a period of time.