Demolition & Confined Spaces

What is the first consideration for any demolition project?

• AWhether the required equipment and machinery is already available on site
• BMinimising the overall cost of the demolition contract for the client
• CHazard surveys identifying asbestos, structures, services, contamination, and structural instability✓
• DThe speed at which the demolition contractor can complete the whole project

Answer: Pre-demolition surveys are essential to identify hazardous materials (asbestos, lead), active utilities, structural hazards, and environmental contaminants.

What is a confined space?

• AA substantially enclosed space where a specified risk, such as lack of oxygen, is reasonably foreseeable✓
• BA small room within a building, regardless of how it is ventilated or accessed
• CAn underground area, regardless of its size, access points, or ventilation
• DA closet or cupboard used for storage, which is safe to enter without prior checks

Answer: Under the Confined Spaces Regulations 1997, a confined space is substantially enclosed and has a reasonably foreseeable specified risk, such as lack of oxygen, toxic gas, fire, drowning or engulfment by a free-flowing solid. Difficult access is not part of the UK test, so tanks, chambers, sewers and poorly ventilated rooms can all qualify.

What must be in place before entry to a confined space under a permit to work?

• AJust the verbal consent of the worker who will be entering the space, given informally on the day
• BThe worker's own common sense on the day is what is required
• CHazard assessment, atmospheric monitoring, rescue plan, permit, and trained personnel✓
• DThe provision of basic personal protective equipment, without atmospheric testing beforehand

Answer: Under the Confined Spaces Regulations 1997, entry is avoided where the work can be done another way. Otherwise a safe system of work based on a risk assessment applies, usually controlled by a permit to work confirming that isolation, air testing and rescue arrangements (reg 5) are in place before entry, with trained, competent people doing the work and any rescue.

What are the hazards associated with asbestos in demolition?

• AA minor irritant to the skin, similar to ordinary household dust
• BHarmless once the building has been left vacant for more than a year or two
• CNo specific hazard exists once the material has been painted over with emulsion
• DInhalation causes mesothelioma, lung cancer, and asbestosis✓

Answer: Asbestos fibre inhalation causes serious lung disease. Demolition of asbestos-containing materials requires licensed contractors and specialised procedures.

When should asbestos removal occur during demolition?

• AIt does not matter at what point
• BBefore any other demolition work begins✓
• CAfter the rest of the demolition work has already been fully completed
• DAt the same time as general demolition, so that both jobs finish together

Answer: Asbestos must be removed and properly disposed of BEFORE general demolition commences to prevent contamination and fibre release.

What is atmospheric monitoring in confined spaces testing for?

• AOxygen levels, toxic gases, and flammable atmospheres✓
• BTemperature and humidity levels, to keep workers comfortable inside
• CThe speed of airflow, to confirm that ventilation fans are switched on
• DThe moisture content of the air, to check for potential water ingress

Answer: HSE's confined spaces ACOP (L101) says to test for oxygen first, then flammable gas, then toxic gases such as hydrogen sulphide and carbon monoxide. Normal air holds 20.9% oxygen and any change is investigated: a small drop impairs judgement and enrichment raises the fire risk. HSE sets no fixed band, but many UK detectors alarm at 19.5% (falling) and 23.5% (rising).

What is a 'Hot Work Permit'?

• APermission to carry out work on site during unusually warm summer weather
• BAuthorisation and precautions for work involving heat (welding, cutting, grinding) to prevent fires✓
• CUnnecessary for construction tasks, regardless of the tools used
• DA type of training course that site operatives complete once a year

Answer: Hot Work Permits authorise high-temperature work and require: fire watch personnel, removal of combustibles, sprinklers/extinguishers ready, and post-work checks.

What should be done with utilities before demolition begins?

• AOnly the gas supply needs disconnecting; other services can safely stay connected
• BDisconnect, cap, and secure all services (gas, electricity, water, drainage) per regulations✓
• CLeft active throughout demolition for the convenience of the site team
• DUtilities do not need to be considered as part of demolition planning

Answer: All live utilities must be identified, safely disconnected, and capped to prevent fire, explosion, electrocution, and contamination during demolition.

What is a confined space rescue plan?

• AUnnecessary provided the entrant is wearing appropriate personal protective equipment
• BSimply having a qualified first aider present somewhere on the wider site
• CDocumented plan for rapid extraction of an incapacitated entrant with trained and equipped rescuers✓
• DAn optional procedure that is only written up if the client specifically requests it

Answer: Rescue plans must document: rescue method, trained rescuers, required equipment (harnesses, lines, ventilation), and coordination with emergency services.

What training is required for confined space entry personnel?

• ATraining limited to operating entry equipment, with no other topics covered
• BWhatever training the workers already receive is enough
• CHazard recognition, atmospheric testing, rescue procedures, emergency response, and permit use✓
• DGeneral site safety induction, with no confined-space-specific content

Answer: Competent personnel must understand confined space hazards, recognise atmospheric dangers, perform testing correctly, and execute rescue procedures.

What is the purpose of a confined space entry permit?

• AAuthorise entry, confirm hazards assessed, controls implemented, and rescue available✓
• BAn optional form that adds administrative delay without improving safety in a meaningful way
• CA verbal nod from the site foreman is what is legally required before entering a confined space
• DConfined space entry needs no formal authorisation as long as the entrant feels confident

Answer: Confined space permits document: hazard identification, atmosphere testing results, rescue plan confirmation, and authorised entrant/attendant/rescue person appointment.

What pre-demolition survey must be completed before demolition starts?

• AA quick visual walk-through by the site manager is enough to rule out hazardous materials
• BA structural photograph of the building's exterior is sufficient evidence before demolition
• CAsbestos survey mandatory; identifies asbestos-containing materials before disturbance✓
• DAsbestos was fully removed from all UK buildings decades ago, so no survey is required

Answer: Licensed asbestos survey required before demolition. Identifies ACM (asbestos-containing materials), determines encapsulation or removal requirements per regulations.

What hazards exist in confined spaces?

• AConfined space hazards build up gradually over several hours, giving ample time to react
• BDust inhalation is the main meaningful risk, since most confined spaces are well ventilated
• CConfined spaces carry no greater risk than an ordinary enclosed room found on a typical site
• DOxygen depletion, toxic gases, engulfment, and high temperatures; rapid incapacitation✓

Answer: Confined space hazards can develop quickly. Air normally contains about 21% oxygen; a low-oxygen atmosphere gives no warning, and very low levels can cause collapse within seconds. Entry needs atmosphere testing, a safe system of work, rescue arrangements and trained people (Confined Spaces Regulations 1997).

What is atmospheric monitoring in confined spaces?

• AContinuous testing of oxygen, toxic gases, and combustible vapours before and during entry✓
• BA single test taken before entry is sufficient, with no further monitoring needed inside
• CAir conditions inside a confined space remain fixed once the initial entry check is complete
• DMonitoring equipment is only required in spaces below ground, not in elevated tanks or vessels

Answer: Under the confined spaces ACOP (L101), the air is tested before entry and monitored continuously where it could change, such as when forced ventilation is used. Normal air holds 20.9% oxygen, and many detectors alarm at 19.5% (falling) and 23.5% (rising). Toxic-gas alarms follow the GB exposure limits in EH40/2005: hydrogen sulphide 5 ppm (8-hour) and 10 ppm (15-minute), carbon monoxide 20 ppm and 100 ppm. Flammable-gas alarms are often set at 10% of the lower explosive limit.

What is a rescue plan for confined space entry?

• ABystanders and passing colleagues can be relied upon to organise an effective rescue if something goes wrong
• BA plan written after entry has begun, once the entrant has reported back on the conditions found inside the space
• CDocument detailing rescue methods, trained personnel, equipment, and communication systems before entry✓
• DUnnecessary provided the entrant carries a mobile phone to call for help if needed

Answer: Rescue plans must identify: rescue method (tripod/harness), trained rescuers on standby, retrieval equipment tested, and communication between entrant and attendant.

What asbestos removal procedures must be followed?

• AAsbestos-containing material can be safely broken out with power tools, provided the operatives wear disposable dust masks
• BAsbestos can be removed using the same methods and tools as ordinary demolition waste
• CLicensed contractor, sealed work area, negative pressure ventilation, wet methods, and proper waste containment✓
• DSmall quantities of asbestos can legally be removed by the ordinary site team without specialist training or a licence

Answer: Most asbestos removal, including all work on sprayed coatings and lagging and most work on insulating board, must be done by an HSE-licensed contractor: the work area is enclosed and kept under negative pressure with HEPA filtration, wet methods keep fibres down, and waste is double-bagged, labelled and sent to a permitted site. Power tools and ordinary demolition methods spread fibres. Lower-risk non-licensed work still needs a risk assessment and asbestos training under the Control of Asbestos Regulations 2012.

What is competent person role in confined space work?

• ATrained individual authorising entry, assessing hazards, ensuring monitoring, and coordinating rescue✓
• BA purely administrative title with no real safety responsibilities on a confined space job
• CAny available worker can take on the role, since competence is not a legal requirement
• DEntry can be approved by whoever is on site at the time, regardless of training or experience

Answer: Competent person must: understand confined space hazards, authorise entry, ensure atmosphere testing, verify rescue plan activation, and monitor throughout work.

What hazards develop during building demolition?

• ADust, asbestos release, structural collapse, noise, vibration, and buried hazards requiring planning✓
• BDemolition can proceed on standard risk assessments used for general site work, since the hazards are no different from routine construction activity
• CDust suppression is the main concern, so provided water spray is used continuously no separate asbestos survey or structural assessment is required
• DOnce services are disconnected and the site fenced off, demolition presents minimal further risk

Answer: Demolition hazards require: asbestos survey, structural analysis, dust suppression (water spray), noise control, vibration monitoring, and demolition sequence planning.

What is the maximum safe duration for continuous confined space entry?

• AWorkers may remain inside for as long as the task requires provided they carry a personal gas monitor, without needing a dedicated attendant outside
• BDuration is only restricted in spaces with a known history of toxic gas
• CEntry duration is set by the permit issuer as a single fixed 4-hour shift regardless of atmosphere, since gas testing at the start covers the whole period
• DDepends on the atmosphere and the permit risk assessment; limit entries, use rotation, and ensure attendant monitoring throughout✓

Answer: Entry time is limited by the permit risk assessment, for example heat, atmosphere and fatigue, with rotation, rest periods and mandatory attendant supervision throughout.