Hazard Recognition · CIH
Industrial Processes and Occupational Hazards: CIH Reference
Study a workplace in this order: process, how exposure is generated, hazardous agent, route of exposure, assessment and control. Five industry tables, then the recognition patterns and the statements that are easy to get wrong.
How to use this page
The examples identify hazards to investigate. They do not mean every listed chemical is present in every workplace: confirm the actual materials, safety data sheets, operating conditions and maintenance tasks.
- Read each row left to right: the task, the agent, how it reaches the worker, the health effect, then what an industrial hygienist checks. Bold text in the last column is the memory aid.
- Section 6 turns the rows into patterns a question stem can describe. Section 7 lists statements that are easy to get wrong.
- Original wording, not a copy of any course text, BGC material or standard. Source links sit under each table. Select sampling methods and interpret results using the specific agent, route, task and assessment criteria that apply.
01 Construction, Renovation & Surface Preparation
Dust, fumes and reactive coatings released when building materials are cut, blasted, mixed or sprayed, plus the outdoor physical hazards that come with the work.
| Industry / task | Common agents or hazards | How exposure occurs | Main health concerns | CIH assessment focus / memory aid |
|---|---|---|---|---|
| Cutting, drilling, grinding, or demolishing concrete, masonry, and engineered stone | Respirable crystalline silica; noise; hand–arm vibration | Mechanical work releases fine particles that can reach the gas-exchange region of the lungs. Dry, high-energy work can generate substantial dust. | Silicosis, lung cancer, chronic respiratory disease; hearing loss and vibration injury | Assess the respirable fraction and crystalline silica content using task-representative sampling. Bulk silica percentage alone does not establish airborne exposure. Silica-containing material + dust-generating work = investigate respirable silica. |
| Abrasive blasting | Silica or other abrasive dust; lead, chromium, or other coating constituents; substrate dust; noise | The abrasive, removed coating, and underlying material can all contribute airborne contaminants. | Respiratory disease and metal-specific toxicity; hearing loss | Identify three sources: abrasive + coating + substrate. A silica-free abrasive does not make the entire process hazard-free. |
| Demolition and renovation | Asbestos-containing materials; lead coatings; silica; microbial contamination where water damage exists | Disturbing older materials releases fibers, dust, and potentially contaminated debris. | Asbestos-related disease, lead toxicity, silica-related disease; biological effects depending on the agent | Use a pre-work material survey and task-specific assessment. Building age suggests possibilities; material identification establishes what is present. |
| Handling wet Portland cement and concrete | Strong alkalinity; soluble chromates where present; dust from dry cement | Wet cement stays against skin or enters boots and gloves; dry material becomes airborne. | Chemical burns, irritant dermatitis, allergic contact dermatitis | Separate wet-cement skin hazards from respirable silica during cutting of hardened concrete. Inspect skin contact, contaminated clothing, and washing arrangements. |
| Mixing and applying epoxy systems | Uncured epoxy components, reactive diluents, amine hardeners; formulation-specific solvents | Mixing, spreading, splashing, and contaminated tools create skin contact; volatile components may also be inhaled. | Irritation and skin sensitization; some components can cause respiratory effects | Evaluate each component and the curing stage. Two-part products create exposure during mixing, application, and cleanup. |
| Spray polyurethane foam and isocyanate-containing coatings | MDI, HDI, or other formulation-specific isocyanates; aerosols; solvents and additives | Spraying creates inhalable droplets, including chemicals with relatively low vapor pressure. | Respiratory sensitization, occupational asthma, irritation, skin sensitization | Assess vapor and aerosol using a suitable isocyanate method. Low volatility does not prevent inhalation exposure when a material is sprayed. |
| Painting, coating, and solvent cleanup | Toluene, xylenes, ketones, acetates, and other formulation-specific solvents; pigment or coating aerosols | Evaporation releases vapor; spraying releases droplets; cleanup can produce short, high exposures. | Irritation, central nervous system effects, dermatitis; additional ingredient-specific effects | Identify the actual formulation, application technique, and peak tasks. Water-based does not automatically mean harmless. |
| Outdoor construction and manual work | Heat, cold, solar ultraviolet radiation, noise, vibration, lifting and awkward postures | Environmental conditions combine with workload, equipment, and work organization. | Heat illness, cold injury, skin and eye damage, hearing loss, musculoskeletal injury | Include physical and ergonomic hazards in the assessment. A chemical inventory is only part of an IH survey. |
Sources: OSHA crystalline silica background, OSHA abrasive blasting fact sheet, OSHA polymer matrix materials, OSHA weatherizing and insulation hazards.
02 Metal Fabrication, Surface Treatment & Foundries
Heat turns metal into fume; baths turn into mist; sand and binders turn into dust and decomposition products.
| Industry / task | Common agents or hazards | How exposure occurs | Main health concerns | CIH assessment focus / memory aid |
|---|---|---|---|---|
| Welding and thermal cutting | Iron and manganese fumes; nickel and chromium, including Cr(VI), in suitable processes; zinc oxide from galvanized metal; ozone, nitrogen oxides, and carbon monoxide depending on conditions | Heat vaporizes material that condenses into fine fume; the arc and surrounding atmosphere can generate gases. Coatings add hazards. | Metal-specific respiratory and systemic effects, metal fume fever, cancer risks for relevant agents; gas irritation or toxicity | Review base metal + filler + coating + process + ventilation. Total welding fume alone may miss a critical constituent. |
| Brazing and soldering | Flux decomposition products; copper and zinc; lead or cadmium where present in the alloy; other formulation-specific metals | Heating filler metals and fluxes releases fumes and gases; residues contaminate hands and surfaces. | Respiratory irritation, metal-specific toxicity; sensitization from some fluxes | Identify the alloy and flux rather than assuming all solder contains lead. Include hand-to-mouth transfer when toxic metals are present. |
| Solvent degreasing | Chlorinated solvents or hydrocarbon solvents, depending on the product | Evaporation from tanks, warm parts, open containers, and cleaning surfaces; splashes create skin exposure. | Central nervous system effects, irritation, dermatitis, and solvent-specific organ or cancer hazards | Examine tank temperature, enclosure, part removal, and maintenance. Heating and surface area affect vapor generation. |
| Machining with metalworking fluids | Fluid mist; additives; tramp oils; microbial contaminants in water-based systems | High-speed tools aerosolize fluid; recirculation and poor maintenance can support contamination; hands contact wet parts. | Dermatitis, occupational asthma, hypersensitivity pneumonitis | Assess fluid aerosol, skin contact, and fluid-management practices. The hazard includes the fluid, its additives, and what grows or accumulates in it. |
| Pickling and chemical cleaning | Hydrochloric, sulfuric, nitric, or other acids; alkaline cleaners, depending on the bath | Heated baths, agitation, and handling generate acid gases, mists, or splashes. | Eye and skin burns; respiratory irritation; chemical-specific effects | Distinguish a gas or vapor from a mechanically generated mist. Select the sampling method for the actual chemical and physical form. |
| Electroplating | Nickel compounds; Cr(VI) in relevant chromium baths; acid mists; cyanides in some processes | Gas bubbles breaking at the bath surface eject droplets; handling and maintenance cause skin contact and splashes. | Cancer risks for relevant agents, sensitization, respiratory irritation, burns; acute cyanide toxicity | Check bath chemistry and mist generation. Acid + cyanide can release hydrogen cyanide. In conventional electrodeposition, the workpiece is the cathode; anodes may be soluble or insoluble. |
| Anodizing | Sulfuric acid mist; other electrolyte hazards, including chromium compounds where chromic acid is used | Electrochemical treatment grows an oxide layer on the workpiece; bath activity can release mist. | Irritation, chemical burns, and electrolyte-specific effects | Anodizing: the workpiece is the anode. Do not assume every anodizing bath uses the same acid or contains chromium. |
| Foundry mold and core making | Silica sand; binder-related phenol, formaldehyde, amines, or isocyanates depending on the system | Sand handling creates dust; binder mixing, curing, and subsequent heating release system-specific chemicals. | Silica-related disease, irritation, sensitization, and binder-specific effects | Assess sand + binder + curing process. Binder chemistry determines the additional sampling targets. |
| Foundry melting and pouring | Metal fumes; carbon monoxide; binder decomposition products; radiant heat | Furnaces and molten metal release fumes and heat; hot metal decomposes mold and core materials. | Metal-specific toxicity, carbon monoxide poisoning, heat strain | Separate combustion gases, metal constituents, and mold decomposition products. Pouring changes the chemistry of the surrounding materials. |
| Foundry shakeout, fettling, and grinding | Respirable silica; metal dust; noise and vibration | Breaking molds and finishing castings release sand and metal particles. | Silicosis and other respiratory effects; hearing loss; vibration injury | Sample high-dust finishing tasks and identify dust constituents. A metal casting task can still be a major silica task. |
Sources: OSHA welding fumes and gases, OSHA metalworking fluids manual, OSHA electroplating fact sheet, NIOSH foundry engineering controls, OSHA hexavalent chromium., NT WorkSafe electroplating guide
03 Chemical Processing, Pulp & Paper, Polymers & Mineral Products
Follow the process stream and the task: normal running, maintenance, curing and cleanup each have their own exposure.
| Industry / task | Common agents or hazards | How exposure occurs | Main health concerns | CIH assessment focus / memory aid |
|---|---|---|---|---|
| Petroleum refining and hydrocarbon processing | Benzene and other hydrocarbons; hydrogen sulfide in sour streams; process-specific gases and chemicals | Leaks, sampling, draining, loading, and opening equipment release process contents. | Benzene-related blood and cancer effects; acute H₂S toxicity; solvent effects; fire and explosion hazards | Trace the process stream and task. Different refinery units and streams have different exposure profiles. |
| Refinery shutdowns, vessel entry, and maintenance | Residual hydrocarbons, H₂S, oxygen deficiency, catalyst dust; potentially pyrophoric deposits | Opening, cleaning, or disturbing equipment releases residues that may not be present in routine area measurements. | Acute poisoning, asphyxiation, dust-related effects; fire or thermal injury | Assess the actual maintenance condition and changing atmosphere. Normal-operation measurements do not establish entry or maintenance conditions. |
| Kraft pulping and chemical recovery | Sodium hydroxide and sodium sulfide in cooking liquor; reduced sulfur gases such as H₂S; process-specific dusts and mists | Cooking, liquor handling, recovery operations, leaks, and maintenance release alkaline chemicals and sulfur compounds. | Chemical burns, respiratory irritation, acute gas toxicity | Kraft cooking liquor: NaOH + Na₂S. Sodium sulfate has a role in the recovery chemistry; it is not the principal active cooking chemical. |
| Pulp bleaching | Chlorine dioxide, hydrogen peroxide, ozone, or elemental chlorine where used | Chemical generation, dosing, leaks, and maintenance can release oxidizing agents. | Respiratory irritation and injury; chemical burns | Identify the mill's actual bleaching sequence. The word “bleaching” does not identify a single chemical. |
| Thermoplastic molding and extrusion | Residual monomers, additives, and thermal decomposition products; hydrogen chloride when PVC decomposes | Heating, overheating, purging, and maintenance can release vapors, gases, and particles. | Irritation and material-specific toxic effects | Review resin, additives, operating temperature, and abnormal conditions. Polycarbonate is a thermoplastic. A finished polymer's properties do not describe all processing emissions. |
| Thermoset resin manufacturing and fabrication | Epoxy components and amine hardeners; styrene in relevant polyester systems; isocyanates in polyurethane systems | Mixing, application, curing, and cleanup expose workers to reactive ingredients; machining cured parts creates dust. | Dermatitis, sensitization, asthma, irritation, and ingredient-specific effects | Distinguish uncured ingredients, curing emissions, and cured-material machining. They require different exposure questions. |
| Ceramic, pottery, and glass batch preparation | Crystalline silica where present; mineral dusts; metal-containing pigments or additives | Dry weighing, mixing, transfer, and cleanup generate airborne dust. | Silica-related disease and ingredient-specific toxicity | Confirm the formulation and crystalline phases. Do not assign one fixed silica percentage to all glass or ceramic products. |
| Kilns, furnaces, and hot glass work | Radiant heat, infrared radiation, combustion gases; material-specific fumes | Hot surfaces and flames produce radiant exposure; combustion and heated ingredients release gases and fumes. | Heat strain, eye hazards, and combustion-related toxicity | Evaluate thermal load, optical radiation, combustion conditions, and feed materials separately. |
| Hydrofluoric acid etching and related processes | Hydrogen fluoride / hydrofluoric acid | Vapor or mist inhalation; splashes or contaminated surfaces cause skin and eye contact. | Severe tissue injury and potentially systemic fluoride toxicity | HF is more than a surface corrosive. Consider concentration, contact conditions, inhalation, and emergency arrangements in the task assessment. |
| Leather tanning and hide processing | Chromium(III) salts in common chrome tanning; sulfides, acids, dyes, solvents, and leather dust depending on the stage | Wet chemical handling, incompatible mixing, finishing, and buffing create different exposures. | Dermatitis, respiratory effects, chemical burns; H₂S poisoning if sulfides are acidified | Follow each stage. Common chrome tanning uses Cr(III); acid + sulfide can release H₂S. Do not automatically classify all tanning chromium as Cr(VI). |
Sources: OSHA petroleum refining processes, OSHA H₂S workplaces, EPA chemical wood pulping, NIOSH hydrogen fluoride emergency response information, ILO leather, fur and footwear.
04 Healthcare, Service Industries, Food & Agriculture
Not every hazard is an industrial chemical: drugs, anesthetic gases, sensitizers, organic dust and manure gases all appear here.
| Industry / task | Common agents or hazards | How exposure occurs | Main health concerns | CIH assessment focus / memory aid |
|---|---|---|---|---|
| Patient care and clinical work | Infectious agents; sharps; lifting demands; workplace violence | Exposure routes include inhalation, mucous-membrane contact, and percutaneous injury; patient handling creates physical strain. | Infection, musculoskeletal injury, traumatic injury | Match controls to the agent, transmission route, and task. Healthcare hazards extend beyond chemicals. |
| Preparing, administering, and cleaning up hazardous drugs | Antineoplastic drugs and other drugs meeting hazardous-drug criteria | Handling powders or liquids, spills, contaminated surfaces, and patient waste can create exposure. | Drug-specific reproductive, carcinogenic, genotoxic, or organ effects | Include dermal and surface contamination assessment. Low air concentrations do not rule out significant contact with contaminated surfaces. |
| Anesthesia administration and recovery | Nitrous oxide and volatile anesthetic agents used at the facility | Leaks, imperfect connections, mask fit, and exhaled anesthetics can release waste gases. | Agent- and exposure-dependent health effects | Assess scavenging, leaks, administration technique, and recovery areas. Exposure can continue after the procedure ends. |
| Sterilization and high-level disinfection | Ethylene oxide, hydrogen peroxide, peracetic acid, glutaraldehyde, or other agents actually used | Loading, unloading, solution handling, leaks, and inadequate aeration can release vapor or aerosol. | Irritation, sensitization, asthma, burns, and chemical-specific long-term effects | Identify the exact process and chemical. “Disinfectant” is a use category, not a toxicological category. |
| Dry cleaning and garment spotting | Perchloroethylene, hydrocarbon solvents, or alternative cleaning agents; spotting chemicals | Loading and unloading, leaks, maintenance, waste handling, and manual spotting release chemicals. | Solvent-specific neurological, skin, organ, or cancer effects; flammability for suitable solvents | Confirm the current machine and solvent system. Changing the main solvent does not eliminate spotting or maintenance exposures. |
| Woodworking and furniture production | Wood dust; formaldehyde from relevant products; finishing solvents and coatings | Sawing, routing, and sanding release dust; gluing and finishing release formulation-specific chemicals. | Respiratory irritation, asthma, dermatitis, and cancer risks associated with relevant wood-dust exposures | Distinguish wood species, composite materials, adhesives, and coatings. Woodworking combines dust and chemical-finishing hazards. |
| Food production, baking, and flavoring | Flour, enzymes, spices; diacetyl or 2,3-pentanedione where present in ingredients or processes | Pouring and mixing powders create dust; heated or handled flavoring mixtures can release volatile compounds. | Occupational asthma from suitable sensitizers; severe lung disease associated with relevant flavoring exposures | Evaluate ingredients and temperature-dependent emissions. Food-safe for ingestion does not establish safety for inhalation. |
| Agriculture and animal housing | Organic dust, endotoxins, molds, ammonia; pesticides where used | Grain and feed handling, animal activity, bedding, and spraying generate mixed exposures. | Respiratory irritation, asthma, organic dust-related illness, and pesticide-specific toxicity | Separate dust, biological components, gases, and pesticide tasks. Total dust mass does not identify endotoxin or a particular organism. |
| Manure pits and manure agitation | Hydrogen sulfide, methane, carbon dioxide, ammonia; oxygen deficiency | Decomposition produces gases; agitation can release large amounts rapidly. | Rapid poisoning, asphyxiation; fire and explosion hazards | Consider sudden peaks and changing atmospheres. Odor is not a reliable H₂S warning, and agitation can sharply increase exposure. |
Sources: NIOSH healthcare chemical hazards, NIOSH hazardous drugs, NIOSH waste anesthetic gases, NIOSH dry-cleaning solvents, OSHA woodworking hazards, NIOSH flavoring-related lung disease, NIOSH manure-pit fatality investigation.
05 Semiconductors, Batteries & Additive Manufacturing
Newer processes with gases, metal powders, electrolytes and resins, where the task matters more than the product.
| Industry / task | Common agents or hazards | How exposure occurs | Main health concerns | CIH assessment focus / memory aid |
|---|---|---|---|---|
| Semiconductor wet processing and cleaning | Hydrofluoric acid, other acids, strong oxidizers, and formulation-specific solvents | Wet benches, chemical transfer, leaks, maintenance, and waste handling create exposure opportunities. | Chemical burns, systemic toxicity from relevant agents, respiratory irritation, solvent effects | A cleanroom protects the product from contamination; it does not by itself establish worker protection. Assess chemical containment and maintenance tasks. |
| Semiconductor doping and deposition | Arsine, phosphine, diborane, silane, and other process-specific gases | Gas delivery failures, equipment opening, maintenance, and disturbed residues can create exposure. | Severe acute toxicity for relevant gases; fire and explosion hazards for pyrophoric or flammable materials | Identify each gas and its decomposition or residual products. Routine operation and chamber maintenance may have different hazards. |
| Lead-acid battery manufacture and recycling | Lead dust or fume; sulfuric acid mist; hydrogen during charging | Powder and paste handling, cutting, breaking, melting, and charging generate different agents. | Lead toxicity, corrosive injury; explosion hazards | Include inhalation, hand-to-mouth transfer, surface contamination, and take-home pathways. Air sampling alone does not describe every lead exposure route. |
| Lithium-ion battery manufacture, handling, and recycling | Chemistry-dependent nickel, cobalt, or manganese compounds; solvents and electrolytes; decomposition products during failures | Powder handling and recycling create dust; spills release electrolyte; thermal runaway releases hot gases and potentially toxic decomposition products. | Material-specific toxicity, irritation, chemical and thermal injury | Identify the cell chemistry and its condition. Intact cells, electrode powders, damaged cells, and thermal runaway are different exposure situations. |
| Polymer and resin 3D printing | Ultrafine particles and VOCs from suitable processes; uncured resin components; cleaning solvents | Printing emissions, resin transfer, washing, curing, and cleanup create different exposures. | Irritation, sensitization from relevant ingredients, and material-specific respiratory effects | Assess the whole workflow. Printing, washing, curing, and sanding are separate exposure tasks. |
| Metal additive manufacturing | Alloy-specific metal powders, including nickel, cobalt, chromium, aluminum, or titanium where used; inert gases | Powder loading, recovery, sieving, cleaning, and finishing release particles; inert-gas leaks can displace oxygen. | Metal-specific toxicity, respiratory effects, oxygen deficiency; combustible-dust hazards where applicable | Evaluate powder composition, particle characteristics, containment, and housekeeping. A finished solid part and its feedstock powder have different exposure potential. |
Sources: OSHA semiconductor device fabrication, OSHA semiconductor substrate manufacturing, OSHA metal scrap recycling, OSHA lithium-ion battery safety, NIOSH additive manufacturing, NIOSH safe 3D printing.
06 CIH Recognition Patterns & Memory Aids
What a question stem describes, and what it should make you investigate.
| What the question describes | What it should make you investigate | Why it matters / memory aid |
|---|---|---|
| Metal heated to a high temperature | Metal fume; coatings; filler materials; combustion or arc-generated gases | Heat changes the exposure form. A bulk metal may become fine airborne fume. |
| Grinding, blasting, cutting, or shakeout | Respirable dust and its hazardous constituents; noise and vibration | Mechanical energy releases particles. Assess what is in the dust, not just how much total dust is present. |
| Spraying a low-volatility liquid | Aerosols, skin deposition, and reactive ingredients | Low vapor pressure does not prevent droplets from entering the breathing zone. |
| An open, heated, or agitated bath | Vapor or gas release; mechanically generated mist; splashes | Temperature, agitation, and bubble bursting affect emissions differently. |
| A two-part resin or reactive coating | Uncured ingredients, hardeners, sensitizers, curing conditions, and cleanup | The ingredient hazard may be greatest before curing is complete. |
| A recirculating water-based fluid | Aerosol, microbial contamination, additives, and skin contact | The fluid changes during use. Fresh product information does not describe every used-fluid hazard. |
| Equipment opened for maintenance | Residues, trapped gases, oxygen deficiency, dust, and process by-products | Maintenance can bypass normal containment. Routine measurements may not represent the task. |
| Dust containing a toxic constituent | Constituent-specific analysis and the relevant particle-size fraction | Mass is not identity. Total dust cannot substitute for silica, lead, or another specific target. |
| Symptoms or biological uptake despite low air results | Skin absorption, surface contact, ingestion, missed peaks, sampling mismatch, or other relevant causes | An air sample answers a defined air-exposure question. It does not measure every route or every time period. |
| A substitute product or changed process | New ingredients, physical forms, temperatures, and exposure routes | Substitution changes the hazard profile. Evaluate the replacement in its actual use conditions. |
07 Important Chemistry & Process Corrections
Statements that are easy to get wrong. Use the correct one.
| Topic | Correct study statement |
|---|---|
| Polycarbonate | Polycarbonate is a thermoplastic, not a thermoset. |
| Polymer safety | A finished polymer should not be described as universally harmless. Heating, decomposition, machining, additives, and residual ingredients can introduce hazards. |
| Chromium in tanning | Common chrome tanning uses chromium(III) salts. Do not automatically equate all chromium-containing processes with chromium(VI) exposure. |
| Electroplating electrodes | In conventional electrodeposition, the object being plated is the cathode. Anodes can be soluble or insoluble, depending on the system. |
| Anodizing electrodes | The workpiece is the anode; an oxide layer grows on its surface. |
| Kraft cooking chemicals | The active cooking liquor contains sodium hydroxide and sodium sulfide. Sodium sulfate belongs in the discussion of makeup and recovery chemistry. |
| Silica content | There is no single silica percentage that accurately describes every ceramic, glass, stone, or construction product. Identify composition and crystalline phases. |
| Hazard recognition | Use an industry label to generate questions; use the actual process, materials, and exposure evidence to answer them. |
Sources are linked under each table and listed on the CIH References page. Independent study content by SPEP; not published by the BGC.