6.4 Hazardous Substances, Asbestos & LEV

6.4 Hazardous Substances, Asbestos & LEV

Quick Answer: Hazardous substances harm via inhalation, skin/eye absorption, ingestion, and injection. Manage them with COSHH logic — assess, prevent/control, monitor, health surveillance, emergencies, and training. Treat asbestos in older buildings as a high-stakes disturbance risk (never DIY). Use LEV to capture contaminants at source and keep it examined and tested. Read labels and SDS; segregate incompatible storage.

Chemical and substance hazards sit in the chemical category of the six-category model, but they appear everywhere: cleaning cupboards, workshops, construction refurbishment, laboratories, kitchens, farms, and offices with printer toners and adhesives. Managing Safely does not turn you into an occupational hygienist, but it does expect you to manage substances like any other significant risk — with structured assessment and reliable controls, not guesswork.

Routes of entry

Harm depends on how a substance gets into or onto the body:

Exam emphasis: inhalation is usually the primary occupational route for chronic disease (asthma, cancer, COPD-type disease, asbestosis/mesothelioma risk pathways). Skin disease (dermatitis) is extremely common and often under-reported. Always think about the route when choosing controls — a mask does nothing for a skin sensitiser if gloves are wrong or missing.

COSHH idea — what managers must drive

In Great Britain, the Control of Substances Hazardous to Health Regulations (COSHH) set the main framework for most hazardous substances (with separate specialist regimes for things like asbestos and lead). Managing Safely teaches the managerial idea of COSHH rather than every technical schedule:

1. Assess the risk from substances used or generated (including process dusts and fumes, not only purchased chemicals).
2. Prevent exposure where reasonably practicable (eliminate the substance or process; substitute a safer alternative).
3. Control exposure adequately when prevention is not possible (priority: engineering and systems of work; PPE last).
4. Maintain, examine, and test control measures (especially LEV).
5. Monitor exposure where needed to show controls work.
6. Provide health surveillance where appropriate (for example asthmagens, sensitisers, chrome, some solvents — as indicated by assessment and OH advice).
7. Plan for accidents, incidents, and emergencies (spills, first aid, evacuation).
8. Ensure information, instruction, and training so people understand labels, SDS, and safe methods.

Prevention and control in practice

Adequate control means reducing exposure to a level that prevents ill health, taking account of any workplace exposure limits (WELs) where they apply. Managers escalate when people report symptoms, when visible dust or strong odours are routine, or when LEV is damaged or ignored.

Labels, SDS, and storage segregation

Labels and packaging

Hazard labels (CLP pictograms and signal words) give immediate warnings: flammable, corrosive, toxic, health hazard, environmental hazard, gas under pressure, and so on. Managers ensure:

• Original labels remain readable
• Decanted containers are labelled — never anonymous bottles of clear liquid
• Workers understand pictograms relevant to their tasks

Safety data sheets (SDS)

Suppliers provide safety data sheets with detailed information on hazards, first aid, fire-fighting, accidental release, handling and storage, exposure controls, physical/chemical properties, toxicology, and disposal. Managers (or competent persons) use SDS to build COSHH assessments and emergency plans. SDS are not wallpaper — they must be accessible and reflected in real methods of work.

Storage segregation basics

Poor storage creates fires, toxic gases, and spill disasters:

• Segregate incompatibles (for example acids away from cyanides or hypochlorite mixes that release chlorine; oxidisers away from flammables — follow SDS and site rules)
• Use bunds / secondary containment for bulk liquids where required
• Control temperature, ignition sources, and ventilation for flammables
• Limit quantities in workrooms to what is needed for the job
• Keep exits and spill routes clear; provide spill kits and train people to use them
• Secure substances from unauthorised use, vandalism, or child access on mixed sites

Asbestos — still a manager’s problem

Asbestos was used widely in buildings for insulation, boards, tiles, coatings, gaskets, and more. Much remains in place in pre-2000 (especially pre-1980s/1990s) stock. Asbestos kills through inhaled fibres causing diseases such as mesothelioma, lung cancer, and asbestosis — often decades after exposure. There is no safe DIY approach to disturbing suspect materials.

What managers must know at overview level

If workers discover a suspicious material mid-job: stop work, restrict access, report, and get competent advice. Do not bag it “carefully” with a broom. Project and exam answers that recommend “just wear a dust mask and carry on” are wrong.

Local Exhaust Ventilation (LEV)

Local Exhaust Ventilation is an engineered system that captures contaminated air at or near the source and removes it from the breathing zone — far more reliable than opening a door and hoping for the best.

Examples:

• Extractor arms on welding bays
• Spray booths and fume cupboards
• On-tool extraction for sanders and cutters
• Capturing hoods on mixing vessels or laboratory processes

Manager responsibilities for LEV

1. Right system for the contaminant and process — wrong hood design fails even if the fan is loud.
2. Correct use — hoods positioned close enough; dampers set; workers trained not to work upwind of the capture zone.
3. Maintenance — filters changed; ducts intact; fans working; damage reported.
4. Thorough examination and test (TExT) — LEV should be thoroughly examined and tested by a competent person at suitable intervals. A common UK benchmark taught for many systems is at least every 14 months (more often for higher-risk or heavily used systems as determined by risk and guidance). Keep records.
5. Indicators — airflow indicators, alarm systems, and simple user checks help daily assurance between formal tests.
6. Do not confuse general building ventilation or a desk fan with LEV. Moving air around can spread contamination.

If LEV is broken, the task may need to stop or switch to an alternative method — not continue with “just RPE.”

Emergency arrangements

Substance emergencies include large spills, uncontrolled releases, fires involving chemicals, and acute over-exposure. Managers ensure:

• Spill kits and neutralisers suited to the substances present
• Trained responders and clear alarm/evacuation rules
• First-aid measures from SDS (eyewash, showers) actually available and working
• Contractors know site rules before bringing their own chemicals on site
• Waste and clean-up does not create a second exposure event

Worked scenarios

Project and exam application

When substances appear on the project:

• Name the substance or process fume/dust, not only “chemicals”
• State the route of entry and who is exposed
• Prefer elimination/substitution/LEV in additional controls
• Include information from SDS, storage, spill response, and any need for health surveillance
• For buildings work, explicitly address asbestos information before disturbance

Common traps

• Treating PPE as the main COSHH control
• Ignoring substances generated by work (dust, fume) because they were not purchased in a drum
• Assuming “a bit of asbestos” is safe if bonded and then drilling it anyway
• Running production when LEV fails “just for today”
• Storing flammables with oxidisers or food with workshop chemicals

Manager checklist

1. Inventory substances used and generated; keep SDS available.
2. Assess with COSHH logic; prioritise prevent then control.
3. Always identify routes of entry — inhalation first among equals for many chronic risks.
4. Maintain and thoroughly examine/test LEV; train users.
5. Manage asbestos information before any building disturbance; never DIY suspect materials.
6. Enforce labels, segregation, spill readiness, and reporting of ill-health symptoms.

Hazardous substances reward careful managers: small everyday decisions about extraction, substitution, and asbestos checks prevent disease that would otherwise appear years later — long after the project form is marked.