those hazards which may cause measurable changes in the body or its functions
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H.R.Sarreshtahdar, MDH.R.Sarreshtahdar, MDOccupational Medicine SpecialistOccupational Medicine Specialist
◦ Chemicals are the most common and significant health hazards
◦ Chemicals can be hazardous for numerous reasons and can combine with other chemicals to make new hazards
Ability of the substance to harm the body
The dose makes the poison Toxicity Depends on : Amount + Duration
Entail a risk due to:
◦Its toxicological properties
◦Its temperature
◦Its radioactivity
◦Displacement of atmospheric oxygen
◦Increase the risk of fire, explosion,…
IARCGroup 1 (carcinogenic)
◦ Benzene, PAH, asbestos, silicaGroup 2A (probably carcinogenic)
◦ Acrylonytrile, vinyl chlorideGroup 2B (possibly carcinogenic)
◦ Acrylamide, lead, chloroformGroup 3 (not classifiable)Group 4 (probably non-carcinogenic)
Causes a REVERSIBLE inflammatory effect on living tissue by chemical action at the site of contact◦Formaldehyde, most solvents
Causes visible Destruction of or IRREVISBLE alterations in living tissue by chemical action at the site of contact◦Phenol, acids and bases
Causes a substantial portion of exposed people to develop an Allergic reaction in normal tissue after repeated exposure to the chemical
Nickel,
Neuro-toxic Cardio-toxic Hepato-toxic Nephro-toxic Hemato-toxic Reproductive toxin
Oculo-toxic Oto-toxic Pulmonary toxin
Vasculo-toxic Dermato-toxic Immuno-toxic
Physical state Chemical structure Duration of exposure Frequency Route Intensity Environmental (temp/humidity/pressure) Individual factors
◦ race/genetics/immune/nutrition/activity/stress/ background disease
Prepared by the chemical manufacturer or importer and describe:◦Physical hazards, such as fire and explosion
◦Health hazards, such as signs of exposure
◦Routes of exposure◦Precautions for safe handling and use
◦Emergency and first-aid procedures◦Control measures
Must provide information about the:
◦Physical and chemical
characteristics
◦Health effects
◦Exposure limits
◦Carcinogenicity (cancer-causing)
Information of the potential health
hazards of chemicals is derived from...
1) Toxicological studies (in vivo, in
vitro)
2) Case reports
3) Epidemiological studies
Acute oral, dermal or inhalation toxicity Provides information on acute health
hazards likely to arise from acute exposure to the substance by the given route, and on the magnitude of acute toxicity of the substance
usually these tests are made with rodents, dermal test quite often with rabbits
LD50/LC50 values (dose level which is caused death to 50% of animals)
Dose-response relationship: lead Dose-response relationship: lead decreased erythrocyte delta-ALAD activityincreased zinc protoporphyrin
anemia
CNS effects
decreased peripheral nerve conductivityNervous paralysis, lead colics
Adapted from Elinder C-G et al., Biologisk monitoring av metallerhos människa. Arbetsmiljöfonden, Uppsala, 1991
Aliphatic (methan, ethylene, …)
Aromatic (benzene, styrene, toluene,…)
Alcohols
Petroleum distillates
Ethers
Esters