I- Definition :
- The solvent is a liquid substance capable of : dissolve(dry cleaning) / extract (petrochemistry) / to suspend (painting) chemicals without altering their chemical constitutions.
- Their industrial use is wide :
– Workers who make repeated use without proper protection can have health problems
– O & rsquo; they are stored in enclosed areas without ventilation can be a source of & rsquo; & rsquo explosion and blaze
– They can cause pollution & rsquo; environment (especially VOC), and contaminate water sources
II- Physical and chemical properties :
1- Polarity :
a- polar solvents : H20, alcohol, acids, bases, ketones, glycol ethers or amines
b- Lipophilic and hydrophobic polar solvents : aliphatic hydrocarbons, aromatic and halogenated
2- steam pressure :
highly volatile : Tv > 50 hPa Volatil : 10 < Tv > 50 Shortly volatile hPa : Tv < 10 hPa
NB : un (volatile organic compound) features a TV > 0,1 hPa
III- use :
Are used as :
- degreasers : cleaning of fabrics and metal parts.
- Dry cleaning
- Extraction of active ingredients in pharmacology
- In manufacturing : gangs, adhesives, Paintings
- Adjuvants and diluents : paints and varnishes.
- strippers : Elimination of paints and fats.
- purifying : in pharmaceutical and perfumery.
- Chemical intermediate for the manufacture of & rsquo; insecticides (surtt OP)
- anesthetics : chlorofome
IV- components :
1- organic solvents :
- saturated and unsaturated aliphatic hydrocarbons : hexane, cyclohexane
- aromatic hydrocarbons : Benzene, xylene, toluene.
- halogenated hydrocarbons : chlorine, brome, fluor
- alcohols : Ethanol and Methanol.
- ketones : Acetone.
- Ethers de glycol
2- No organic :
- sulfur derivatives
- nitrogen derivatives
- aqueous products
V- Toxicity :
1- Routes & rsquo; intoxication :
- Respiratory : inhalation of volatile particles in suspension in & rsquo; air.
- cutaneous : Favored by the lipid solubility of these substances.
- Digestive : often accidental.
2- Diffusion :
- The solvents are fixed to the tissues (high fat) and then metabolized in the liver level.
3- Elimination :
– Expired air.
NB : mercury n & rsquo; is not a solvent, l & rsquo; Water is a solvent.
WE- Symptomatology :
- Some symptoms are common to many solvent with specificities for each toxic.
1- acute intoxication :
– The route of & rsquo; s biggest intoxication in the workplace is the pulmonary route.
– Favored by affinities of these toxic for the rich in fat bodies (liposolubilité).
- massive airway irritation (mouth, nose, VRS and VRI) : Some solvents release caustic as phosgene (carbonyl chloride) and & rsquo; HCl causing a lesion OAP and acute respiratory failure.
- Altered CNS : manifestation ébrio-narcotique (headaches, nausea, intoxication, dizziness). If & rsquo; mass poisoning, l & rsquo; evolution can be towards a deep coma.
- achievement heart : halogenated solvents are responsible for cardiac arrhythmias (71 with the number of incorporated chlorine).
- Reaching mucocutaneous : irritation, burn in case of & rsquo; massive exposure, conjunctivitis (intérêtd & rsquo; immediate washing with & rsquo; running water).
- Cytolyse, acute hepatitis
- anuric kidney failure
2- chronic intoxication :
- chronic dermatoses : appearance lichenifie, crevasse especially touching hands
- Contact dermatitis : preferably serving at the exposed parts : mains, face very itchy erythematous and keratotic.
- neurological impairment : grouped under the & rsquo; name "Solvent psycho-syndrome 'is made of :
– Sleep disorder.
– Memory impairment.
These symptoms may be revised at the beginning of & rsquo; intoxication
- optic neuritis : carbon disulfide
- Hemato-toxicity : Myelosuppression (Benzene is forbidden), méthomoglobinisant (nitrates)
- Hepato renal impairment : IRC and IH cirrhosis.
- Reproductive effects : precaution in pregnant women (ABRT).
- carcinogenicity : hepatoma, hepatocellular carcinoma
NB : CMR (carcinogenic, mutagenic, reprotoxique)
VII- technical prevention :
- Ensure proper labeling : good packaging and adequate storage.
- To replace very unsafe products as "Benzene".
- Work in isolation.
- Capturing the source vapors in emissions, volatile or suspended particles.
- Ensure good ventilation of work.
- Regularly check the concentrations of toxicants in & rsquo; air CMA TLV.
- Equipping workers of personal protective equipment (glasses, gloves, clothing, shoe…)
- Separate street clothes of those work.
- daily showers.
VIII- medical prevention :
- Medical examination has fattening : kidney away, hepatic, respiratory, cardiac, dermatological, narco- dependent.
- periodic inspection : neurological and skin examination.
- spontaneous visit : report symptoms to their exhibitions
Dr Boumendjel's course – Faculty of Constantine