What is the difference between petroleum distillates and petrochemicals? Is one more toxic than the other?

Petrochemicals are any chemicals made from coal tar or crude oil. 

Petroleum distillates are petrochemicals that have been distilled in a refinery and then usually processed further and purified in some manner. There are many different types with completely opposite characteristics and uses. 



Distillation is the basic process used to separate and purify the components of crude oil. Crude oil is a complex mixture of hydrocarbons with impurities like sulfur, nitrogen and small amounts of metal. During distillation, the oil is heated in a large closed vessel 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 on. 


Though all petrochemical products start as a distillate of petroleum, not all petrochemical products fall into the classification of "petroleum distillates." Specifically, petroleum distillates include mineral spirits, kerosene, white spirits, naphtha, and Stoddard solvent. These products may contain trace amounts of benzene and other aromatic hydrocarbons such as toluene and xylene which have similar toxic effects. 



Any product that contains a petroleum distillate in its formula must be labeled with the phrase "contains petroleum distillates" regardless of the actual distillate used. This is so doctors and emergency medical personnel will know how best to treat those who might accidentally drink the product. If a product contains petroleum distillates, the medical personnel may elect not to induce vomiting. 



According to the Consumer Product Safety Commission:

The toxicity of petroleum distillates and other hydrocarbons affects the respiratory system. Aspiration of small amounts of these chemicals directly into the lung, or into the lung during vomiting of an ingested chemical, can cause chemical pneumonia, pulmonary damage, and death. Petroleum distillates with low viscosity, such as gasoline, kerosene, and mineral seal oil, possess the greatest potential for aspiration.

All household products that contain 10 percent or more of petroleum distillates, or benzene, toluene, xylene, or turpentine, are required to have hazard warnings by regulations under the Federal Hazardous Substances Act.

"Petroleum distillates" can also be an ingredient in a product. In this case, it is a mix of petrochemicals that are all petroleum distillates. The mix can vary from batch to batch, so we don't know exactly what is in it. It may contain chemicals of varying toxicities. Pesticides commonly contain petroleum distillates as well as the actual pesticide itself, making them doubly toxic.

I'm not a chemist, so if anyone reading this would like to jump in and correct any errors I've made on this or explain further, please do so!

Debra :-)

This answer was provided by our friend, Debra Lynn Dadd. Hailed as "The Queen of Green" by the New York Times, Debra Lynn Dadd has been a pioneering consumer advocate since 1982, specializing in products and lifestyle choices that are safer for human health and the environment. She is the author of Home Safe Home.