SOLVENTS

PHYSICAL AND CHEMICAL PROPERTIES:

SolubilityFlammability

VolatilityChemical structure

PHARMACOKINETICS OF SOLVENTSRoute of exposure:

1-pulmonary 2-percutaneous

Distribution :Metabolism:

1-toxification 2-detoxification

Excretion: 1-expiration

2-urine

BIOLOGICAL MONITORING

Less value for solvents because of:

1-rapid absorption and excretion

2-acute high brief exposure is more important than accumulation exposure.

HEALTH EFFECTS OF SOLVENTS

Skin disorders:20% of occupational dermatitis.

Defatting property.Concentration and time of exposure.Clothing and gloves.

Finding: irritation, dryness, scaling, tingling,

itching . patch test in a few instances.

Treatment & prevention: emollient, topical steroid,

good hygiene, education, engineering control.

central nervous system:

acute effects: euphoria, anesthetic, headache, confusion, disorientation,

drowsiness…, symptoms resolved under 24 hours.

chronic effects: neurobehavioral disorders, cortex atrophy, Alzheimer, vestibulo-oculomotor disorder.

diagnosis: 1- Hx of exposure 2-clinical finding 3- role out of other disease

PERIPHERAL NERVOUS SYSTEM

Sensorymotor nuropathy:symmetric, ascending, distal axonopathy.

Common cause:

CS2, n,hexan, methyl n buthyl ketone.

Others:

Terigeminal anesthesia = TCESensory neural HL= styreneVisual disorder = tuloene, styrene.

Diagnosis: NCV, EMG, nerve biopsy, clinical findings.

DDx: diabetes mellitus, alcoholism, drugs

Treatment: cut of exposure.

Prognosis: depends on damage and removal time.

Respiratory system:Findings: mucosal irritation, cough, pulmonary edema, hypoxia.

Heart:cardiac sensitization to epinephrine effects.methylene chloride acts on heart like as CO.

Liver: hepatotoxicity of halogenated hydrocarbons.

Finding: RUQ pain, nausea, vomiting, icter. Serum bile acid rising. Antipyrine metabolism rising.

DDx: alcoholic hepatitis.

kidney: TCC= acute tubular necrosis.

toluene= distal RTA.

ethylene glycole= renal stone.

RPGN in case reports.

Findings: polyuria, proteinuria, glucosuria, RTA.

Blood: aplastic anemia= benzen, chlorinated

hydrocarbons.

hemolytic anemia= glycol ethers.

Cancer potential:benzen, halogenated hydrocarbons, mixed solvents.

Reproductive system: increased risk of SA, malformation, time of fertility,

FAS, oligospermia & azospermia(in exposed men)

PREVENTION OF SOLVENT TOXICITY

1 -selection & substitution of solvent.

2-engineering controls.

3-personal protection.