What is the cost of mineral spirits.......is it worth it?

Inhalation studies on animals showed that the hydrocarbons, which compose mineral spirits, may be stored in body fats and can enter the brain days after exposure to induce delayed effects. Stoddard solvent has been shown to cause seizures in rats, cats, and dogs, and bronchitis in guinea pigs. The International Agency for Research on Cancer (IARC) classifies "petroleum distillates" as probable human carcinogens.

There are no safe organic solvents, only more and less toxic ones. All organic solvents can affect the nervous system, respiratory system, skin, eyes, and internal organs to some degree. Solvents are also implicated in damage to both the male and the female reproductive systems." Source: UIC Health and Safety in the Arts Library.

A parts washer is the perfect machine to "maximize" the inhalation of the parts washer solvent. Most contain benzene.

The aromatic hydrocarbons are identified as chemicals of interest for health risk assessments at most petroleum-contaminated sites and for sites affected by petroleum solvent. Benzene is the only aromatic hydrocarbon classified by the U.S. Environmental Protection Agency and other health and environmental agencies as a "known human carcinogen," and therefore, is the primary focus of many petroleum hydrocarbon risk assessments. Exponent has conducted hundreds of site risk assessments where benzene was a chemical of concern. The potential exposure to benzene at a petroleum-contaminated site depends on the concentrations of benzene in the soil, water, and air, and the frequency and duration of expected human contact with the contaminated media. If the petroleum release was gasoline from an underground tank, benzene will likely be found in soils and possibly also in shallow groundwater and air. The volatilization of benzene in subsurface soils and shallow groundwater and its migration into buildings (vapor intrusion), have recently become a risk assessment focus that has led to the reopening of Records of Decision (RODs) at a number of sites. Benzene and the other aromatic hydrocarbons are taken up through the skin, lung, and digestive system, so all three routes of exposure (dermal uptake, inhalation, and incidental ingestion) need to be considered in assessing health risks.

http://www.benzene-myelogenous-leukemia.com/html/risks.html

http://www.benzene-exposure-attorneys.com/whatisbenzene.shtml  

http://www.toxictorts.com/learning_center.shtml

http://health.nytimes.com/health/guides/poison/mineral-spirits/overview.html