Chemical Hazards Flashcards

What does the SDS section on 'first aid measures' provide and how should it be used?

Answer: Immediate first-aid actions for each exposure route (inhalation, skin, eye, ingestion) — must be reviewed before work with any chemical, not only after an incident

SDS Section 4 (First Aid Measures) specifies immediate response for each route of exposure: inhalation (remove from exposure, fresh air, oxygen/resuscitation), skin (remove contaminated clothing, wash with water), eyes (irrigate with water for specified minutes), ingestion (do not induce vomiting unless specified). First aiders must be familiar with SDSs for regularly used chemicals before incidents occur.

What is the hazard of working with strong oxidising agents in the Gulf context?

Answer: Oxidisers (concentrated hydrogen peroxide, nitric acid, permanganates, chlorates) can spontaneously ignite or cause explosive reactions when in contact with organic materials or contaminated surfaces — even small contamination is dangerous

Strong oxidizers provide oxygen for combustion, causing ordinary materials (organic solvents, wood, fabrics, human skin) to ignite or react violently without an external ignition source. They require: storage away from all organic materials, dedicated equipment, no shared pipework with other chemicals, and strict contamination controls. Gulf water treatment, mining, and chemical industries use significant oxidizer quantities.

What is the purpose of atmospheric monitoring in confined spaces before entry?

Answer: To measure oxygen concentration, flammable gas/vapour concentrations (% LEL), and toxic gas levels (H₂S, CO) before entry and continuously during occupation — conditions can change at any time

Confined space atmospheres can be oxygen-deficient, oxygen-enriched, toxic (H₂S, CO), or flammable (methane, hydrocarbon vapours). Conditions can change rapidly due to ingress of gas, biological decomposition, or work activities (welding, painting). Testing must occur before entry using calibrated instruments, and continuous monitoring maintained throughout. Calibration of monitors must be current.

What specific control measures are required for cytotoxic drug handling in Gulf hospitals?

Answer: Preparation in a Class II BSC, double chemotherapy-grade gloves, chemo-rated gown, eye/face protection, closed-system drug transfer devices, dedicated waste containers, spill kit, and worker health monitoring

Cytotoxic drugs are carcinogenic, mutagenic, and teratogenic. Healthcare workers preparing or administering them face occupational exposure risk. Controls: preparation in a biological safety cabinet (Class II B2), CSTD (closed system transfer devices), specific chemo-rated PPE (not standard disposables), safe disposal of waste, spill kits, urine monitoring for specific drugs, and pregnant worker exclusion.

What are the specific hazards of pesticide use in Gulf agricultural and pest control operations?

Answer: Organophosphate and carbamate pesticides inhibit acetylcholinesterase causing acute cholinergic toxicity (SLUDGE: salivation, lacrimation, urination, defecation, GI distress, emesis); chronic exposure linked to neurological damage and cancer

Organophosphate and carbamate pesticides (commonly used in Gulf agriculture and pest control) cause cholinergic crisis by inhibiting acetylcholinesterase. Acute symptoms follow SLUDGE mnemonic. Chronic exposure is linked to neurological effects and certain cancers. Full PPE (impermeable suit, supplied-air respirator for confined applications), biological monitoring (blood cholinesterase), and restricted re-entry intervals are required.

What is the significance of 'permissible exposure limit' (PEL) versus 'threshold limit value' (TLV) for Gulf employers?

Answer: PELs are legally enforceable US OSHA limits; TLVs are guidance values from ACGIH that are often more current and protective — Gulf employers typically use TLVs as they represent best available science

OSHA PELs (established 1971) are legally enforceable in the US but are outdated for many substances. ACGIH TLVs are updated annually based on current toxicological evidence and are often significantly more protective than OSHA PELs. Gulf employers and HSE professionals use TLVs as the best-available benchmark for exposure evaluation, supplemented by national OELs where published.