Occupational asthma refers to new onset asthma or the recurrence of previously quiescent asthma directly caused by exposure to an agent at workplace. It is an occupational lung disease and a type of work-related asthma. Agents that can induce occupational asthma can be grouped into sensitizers and irritants.Grains, flours, plants and gumsOccupationAgentBakers, millersWheatChemists, coffee bean baggers and handlers, gardeners, millers, oil industry workers, farmersCastor beansCigarette factory workersTobacco dustDrug manufacturers, mold makers in sweet factories, printersGum acaciaFarmers, grain handlersGrain dustGum manufacturers, sweet makersGum tragacanthStrawberry growersStrawberry pollenTea sifters and packersTea dustTobacco farmersTobacco leafWoollen industry workersWoolAnimals, insects and fungiOccupationAgentBird fanciersAvian proteinsCosmetic manufacturersCarmineEntomologistsMoths, butterfliesFeather pluckersFeathersField contact workersCricketsFish bait breedersBee mothsFlour mill workers, bakers, farm workers, grain handlersGrain storage mites, alternaria, aspergillusLaboratory workersLocusts, cockroaches, grain weevils, rats, mice, guinea pigs, rabbitsMushroom cultivatorsMushroom sporesOyster farmersSea pineapples (Hoya)Pea sortersMexican bean weevilsPigeon breedersPigeonsPoultry workersChickensPrawn processorsPrawnsSilkworm sericulturersSilkwormsZoological museum curatorsBeetlesChemicals/MaterialsOccupationAgentAircraft fittersTriethyltetramineAluminum cable solderersAminoethylethanolamineAluminum pot room workersFluorineAutobody workersAcrylates (resins, glues, sealants, adhesives)Brewery workersChloramine-TChemical plant workers, pulp mill workersChlorineDye weighersLevafix brilliant yellow, drimarene brilliant yellow and blue, cibachrome brilliant scarletElectronics workersColophonyEpoxy resin manufacturersTetrachlorophthalic anhydrideFoundry mold makersFuran-based resin binder systemsFur dyersPara-phenylenediamineHairdressersPersulphate saltsHealth care workersGlutaraldehyde, latexLaboratory workers, nurses, phenolic resin moldersFormaldehydeMeat wrappersPolyvinyl chloride vapourPaint manufacturers, plastic molders, tool settersPhthalic anhydridePaint sprayersDimethylethanolaminePhotographic workers, shellac manufacturersEthylenediamineRefrigeration industry workersCFCsSolderersPolyether alcohol, polypropylene glycol Isocyanates and metalsOccupationAgentBoat builders, foam manufacturers, office workers, plastics factory workers, refrigerator manufacturers, TDI manufacturers/users, printers, laminators, tinners, toy makersTDIBoiler cleaners, gas turbine cleanersVanadiumCar sprayersHexamethylene diisocyanateCement workersPotassium dichromateChrome platers, chrome polishersSodium bichromate, chromic acid, potassium chromateNickel platersNickel sulphatePlatinum chemistsChloroplatinic acidPlatinum refinersPlatinum saltsPolyurethane foam manufacturers, printers, laminatorsDiphenylmethane diisocyanateRubber workersNaphthalene diisocyanateTungsten carbide grindersCobaltWeldersStainless steel fumesDrugs and enzymesOccupationAgentAmpicillin manufacturersPhenylglycine acid chlorideDetergent manufacturersBacillus subtilisEnzyme manufacturersFungal alpha-amylaseFood technologists, laboratory workersPapainPharmacistsGentian powder, flaviastasePharmaceutical workersMethyldopa, salbutamol, dichloramine, piperazine dihydrochloride, spiramycin, penicillins, sulphathiazole, sulphonechloramides, chloramine-T, phosdrin, pancreatic extractsPoultry workersAmprolium hydrochlorideProcess workers, plastic polymer production workersTrypsin, bromelinWoodsOccupationAgentCarpenters, timber millers, woodworkersWestern red cedar, cedar of Lebanon, iroko, California redwood, ramin, African zebrawoodSawmill workers, pattern makersMansonia, oak, mahogany, abiruanaWood finishersCocabollaWood machinistsKejaat Occupational asthma refers to new onset asthma or the recurrence of previously quiescent asthma directly caused by exposure to an agent at workplace. It is an occupational lung disease and a type of work-related asthma. Agents that can induce occupational asthma can be grouped into sensitizers and irritants. Sensitizer-induced occupational asthma immunologic form of asthma which occurs due to inhalation of specific substances (i.e., high-molecular-weight proteins from plants and animal origins, or low-molecular-weight agents that include chemicals, metals and wood dusts) and occurs after a latency period of several weeks to years. Irritant-induced (occupational) asthma is a non-immunologic form of asthma that results from a single or multiple high dose exposure to irritant products. It is usually develops early after exposure; however can also develop insidiously over a few months after a massive exposure to a complex mixture of alkaline dust and combustion products, as shown in the World Trade Center disaster. Unlike those with sensitizer-induced occupational asthma, subjects with irritant-induced occupational asthma do not develop work-related asthma symptoms after re-exposure to low concentrations of the irritant that initiated the symptoms. Reactive airways dysfunction syndrome (RADS) is an severe form of irritant induced asthma where respiratory symptoms usually develop in the minutes or hours after a single accidental inhalation of a high concentration of irritant gas, aerosol, vapor, or smoke. Another type of work-related asthma is work-exacerbated asthma (WEA) which is asthma worsened by workplace conditions but not caused by it. WEA is present in about a fifth of patients with asthma and a wide variety of conditions at work, including irritant chemicals, dusts, second-hand smoke, common allergens that may be present at work, as well as other “exposures” such as emotional stress, worksite temperature, and physical exertion can exacerbate asthma symptoms in these patients. Both occupational asthma and work-exacerbated asthma can be present in an individual. A number of diseases have symptoms that mimic occupational asthma, such as asthma due to nonoccupational causes, chronic obstructive pulmonary disease (COPD), irritable larynx syndrome, hyperventilation syndrome, hypersensitivity pneumonitis, and bronchiolitis obliterans. Like other types of asthma, it is characterized by airway inflammation, reversible airways obstruction, and bronchospasm, but it is caused by something in the workplace environment. Symptoms include shortness of breath, tightness of the chest, coughing, sputum production and wheezing. Some patients may also develop upper airway symptoms such as itchy eyes, tearing, sneezing, nasal congestion and rhinorrhea.