Organic solvents skin exposure

Toxicology. The nitroparaffins have minimal effects by way of actual contact. There were neither systemic effects nor irritation in dermal studies in rabbits. Human exposure of a prolonged or often-repeated nature has led to low grade irritation attributable to removal of oil from the skin, an effect produced by most organic solvents. Eye irritation potential of all four nitroparaffins has been deterrnined in rabbits. Other than a transient slight redness and some lachrymation, no effects were noted. The average Draize score was 0.0. The acute oral toxicity, LD q, of all four nitroparaffins has been deterrnined in the rat (Table 8). 

Vapor pressure is important simply because a compound that is easily vaporized can also readily cause a marked exposure through the lungs. Organic solvents are good examples of volatile compounds, and known to cause marked exposure via the lungs, in addition to exposure via the skin. ... 

Typically, there is a latent period with no visible effects between the time of exposure and the sudden onset of symptoms. This latency can range from 1 minutes to 18 hours and is affected by factors such as the amount of agent involved, the amount of skin surface in contact with the agent, and previous exposure to materials that chap or dry the skin (e.g., organic solvents such as gasoline or alcohols). Moist, sweaty areas of the body are more susceptible to percutaneous penetration by solid nerve agents. 

The permeability of the skin to a toxic substance is a function of both the substance and the skin. The permeability of the skin varies with both the location and the species that penetrates it. In order to penetrate the skin significantly, a substance must be a liquid or gas or significantly soluble in water or organic solvents. In general, nonpolar, lipid-soluble substances traverse skin more readily than do ionic species. Substances that penetrate skin easily include lipid-soluble endogenous substances (hormones, vitamins D and K) and a number of xenobiotic compounds. Common examples of these are phenol, nicotine, and strychnine. Some military poisons, such as the nerve gas sarin (see Section 18.8), permeate the skin very readily, which greatly adds to then-hazards. In addition to the rate of transport through the skin, an additional factor that influences toxicity via the percutaneous route is the blood flow at the site of exposure. 

Phenoxyethanol produces a local anesthetic effect on the lips, tongue, and other mucous membranes. The pure material is a moderate irritant to the skin and eyes. In animal studies, a 10% v/v solution was not irritant to rabbit skin and a 2% v/v solution was not irritant to the rabbit eye. Long-term exposure to phenoxyethanol may result in CNS toxic effects similar to other organic solvents. 

SLE is a chronic autoimmune connective tissue disease characterized by inflammation and injury to the joints, tendons, and other connective tissues. Organs affected include the lungs, heart, blood vessels, brain, kidneys, and skin. SLE onset is associated with exposure to silica. Though earlier studies have suggested that organic solvent exposure can also be causative for SLE, more recent studies have refuted thisJ2,3,9 No literature references were found associating SLE onset with exposures to chemical mixtures. 

C/77°F) readily dissolves in most organic solvents. This compound is structurally similar to 2,4-D, except that one of the Cl atoms in the aromatic ring is substituted with a methyl group. Toxic properties are expected to be similar to 2,4-D. It is moderately toxic by ingestion, inhalation, and possibly other routes of exposure. Skin contact can cause irritation. 

The primary sources of PCP in humans include direct intake by way of diet, air, or water and through contact with PCP-contaminated materials. It is now established that PCP is taken up by female rhesus monkeys via the skin from PCP-contaminated soils monkeys accumulated up to 24% of the PCP in contaminated California soils over a 24-h period. In humans, the chief routes of exposure in an industrial setting are by way of inhalation and skin contact. Percutaneous absorption is significantly enhanced when PCP is dissolved in organic solvents, such as fuel oil, or when PCP comes in contact with open cuts... 

Solvents can cause dermatitis in a number of ways first, they dissolve and remove the natural body oils from the skin, which then dries and cracks second, chlorinated solvents actually attack the outer layer and may cause red blotches and blisters if kept in contact with the skin. Employees using solvents must be informed of the hazards resulting from skin contact. Solvents should not be used as skin cleaners. No worker with a skin irritation should be employed in a process involving exposure to organic solvents. 

Monitoring methods for dermal exposure have not been standardized as well as the methods to assess inhalation exposure. Adsorptive pads of activated carbon cloth can be used for monitoring of dermal exposure to organic solvents. Patches are attached on various parts of the body under the clothing and the amounts analyzed are then multiplied with the areas of each body region.Exposure assessment is complicated by the contribution of solvent vapor on the samples. Because the adsorptive surface of activated carbon is much larger than that of the skin, pads will adsorb much more solvents than the skin. However, only exposure to liquid phase is usually significant therefore, the adsorbed vapor should be subtracted from the total mass analyzed. However, this makes the exposure assessment... 

Skin absorption is the second most important route for solvent entry into the body and at times is much more significant than inhalation. The reason is that absorption of organic solvent vapors by inhalation at the threshold limit value is insignificant and is less than 2% of the amount absorbed via inhalation under the same exposure conditions. In contrast, solvents may be absorbed through the skin in significant amounts even at below the threshold limit value. Factors that effect the skin absorption of solvents include the composition of... 

Inhalation is usually clearly the most important route for occupational exposure to solvents. Organic solvents also enter the body through the skin. For some solvents, especially for alkoxyalcohols (glycol ethers) and their acetates, this is even the main route of absorption. Even the skin uptake of vapor can be significant for these compounds. Dermal absorption of vapors is, however, usually negligible and contact with liquid is required. Increased workload and heat enhance both inhalation and dermal absorption. Skin contamination may also lead to oral uptake due to eating and smoking but this is of minor importance for volatile solvents. 

---