Volcanic eruptions — Module 3 · Phase 2: During

When an eruption, a dangerous increase in volcanic activity, or an official action order is reported, the household or community must immediately activate the plan established beforehand.

Rumors, unverified messages, or social media posts must never be allowed to replace the official instructions.

During a volcanic crisis, conditions can change rapidly.

An eruption can go through different eruptive pulses or phases and intensify again.

An evacuation order must be carried out without delay. Every household or community must implement the plan already established.

Before leaving the home or community spaces, only if there is enough time and doing so does not mean exposing yourself to danger, those in charge may:

Take the emergency supplies prepared in advance,

bring essential documentation,

assist vulnerable people,

secure pets or other animals that can be evacuated according to the plan,

close doors and windows,

take the measures previously established for gas, electricity, water or other services.

During the evacuation, use the routes indicated by the authorities. Do not improvise alternative paths simply because they seem shorter.

In lahar hazard zones, avoid entering or staying in riverbeds, creeks, ravines, valleys, and other areas officially identified as dangerous.

The safe direction will depend on the specific threat and on the maps and routes established for each territory.

In certain situations, especially when the main problem is ashfall, the authorities may recommend staying temporarily inside a building.

In that case:

Go into the building,

keep people and animals indoors,

close doors and windows,

reduce the entry of outside air when the authorities recommend it,

close or adjust the ventilation and air conditioning systems according to the procedure already established,

avoid opening doors,

move to the area identified in advance for sheltering in place when applicable,

keep emergency supplies available,

continue listening to the official communications.

The sealing materials prepared beforehand may be used to reduce the entry of ash through major openings.

Staying inside a building can considerably reduce exposure to ash, but it does not provide adequate protection against every volcanic threat.

A conventional building must not be considered a safe shelter against:

• Pyroclastic flows,
• certain lahars,
• lava that directly reaches the building,
• major ballistic projectiles,
• structural fires,
• building collapse,
• dangerous concentrations of certain gases.

When volcanic ash begins to fall, exposure must be reduced to a minimum.

Whenever possible:

• Stay indoors,
• close doors and windows,
• keep children and vulnerable people inside,
• keep animals protected,
• reduce unnecessary physical activity,
• avoid travel,
• protect food and water,
• follow the official instructions.

Avoid going outside while ash is falling, unless it is necessary to evacuate, carry out an essential function, or respond to an emergency.

When it is unavoidable:

Use appropriate respiratory protection,

use eye protection,

cover as much skin as possible,

limit exposure time,

avoid unnecessary physical effort,

return to a protected environment as soon as possible.

To reduce the inhalation of ash particles, certified particulate respirators —such as N95, P2, FFP2, or equivalent— should preferably be used and fitted correctly.

Keep in mind that:

The respirator must fit the face correctly,

it must cover the nose and mouth,

facial hair can make it harder to achieve a proper seal,

a respirator designed for particles does not protect against volcanic gases,

models designed for adults may not fit children correctly,

people with certain respiratory or cardiovascular conditions may have difficulty using some respirators.

During ashfall, protective goggles that reduce the entry of particles should be used whenever it is necessary to stay outdoors.

• Goggles or tight-fitting safety glasses offer superior protection compared to regular eyeglasses.

• Sunglasses can partially reduce direct contact with larger particles, but they do not replace proper eye protection.

• Avoid wearing contact lenses during ashfall when possible, since particles can become trapped between the lens and the eye and cause irritation or injury.

• Do not rub your eyes if ash gets into them.

Exposure to ash can worsen asthma and other respiratory conditions.

If ash is falling, apply the procedures already established to limit it from entering the building.

When appropriate and it can be done safely:

Close outside air intakes,

adjust the air conditioning systems,

use recirculation modes when appropriate,

check the filters,

avoid using equipment that draws in large amounts of outside air contaminated with ash.

Fine ash can get into equipment and cause abrasion, blockages, overheating, or failures.

During significant ashfall:

Protect sensitive equipment,

keep the spaces where it is located closed,

reduce the entry of ash,

avoid use of exposed equipment,

follow the manufacturer’s or technical staff’s instructions.

Whenever the authorities have not ordered an evacuation and there is no other urgent need, avoid driving during significant ashfall.

Ash can:

Drastically reduce visibility,

hide signage and obstacles,

make surfaces slippery,

affect filters,

get into engines,

wear down components,

affect windshield wipers and windshields.

Lahars can be one of the most dangerous hazards of a volcanic crisis. They can occur during an eruption and can also be associated with rain, snowmelt, or other conditions capable of mobilizing volcanic material.

If there is a lahar warning:

• Act immediately;
• follow official routes;
• leave the areas identified as threatened;
• move away from channels, rivers, creeks, ravines, and affected valleys;
• head for the safe zones established by the authorities;
• do not cross bridges or channels if there is a flow warning;
• do not stop to watch the phenomenon.

Near certain volcanoes, blocks and fragments ejected during explosions can fall.

If a person is unexpectedly exposed to falling fragments and cannot evacuate immediately, they should seek available protection from impact while following emergency instructions.

Volcanic gases can be dangerous even when there is no heavy ashfall.

While significant ashfall continues, the priority is not cleaning but protecting people and maintaining essential functions.

Continuous cleanup can:

• Increase exposure,
• resuspend particles,
• waste protective equipment unnecessarialy,
• force people to stay outdoors,
• create a risk of falling.

A significant accumulation of ash can increase the load on a structure.

Climbing onto a roof can carry risks of:

Falling,

low visibility,

slippery surfaces,

respiratory exposure,

falling volcanic material,

structural collapse.

During an emergency, pets must be kept under control.

When applicable:

Keep dogs on a leash or harness,

keep cats and other small animals in carriers,

prevent them from going outside during ashfall,

provide protected water and food,

prevent them from eating visibly contaminated food,

keep them indoors when it is safe to do so,

evacuate them together with those responsible for them when the plan and the authorities allow it.

If animals were evacuated as a precaution, they must not be brought back while the emergency continues.

If they remain in the area, the instructions of the veterinary, agricultural, and civil protection authorities must be followed.

When possible and safe:

Keep them away from dangerous areas,

protect the water,

protect feed and forage,

reduce their exposure to ash,

keep them appropriately sheltered.

Those designated in advance must provide assistance to anyone who needs it.

Do not separate a person from:

• Their mobility devices,
• medications,
• assistive devices,
• communication items,
• service animals,
• other essential items.

Families and those responsible for children or other dependent people must strictly apply their protection and reunification procedures.

During the emergency:

• Keep the group organized,
• prevent children from going outside unnecessarily,
• stop them from playing with the ash,
• make sure protective equipment is used correctly,
• take a head count,
• keep records,
• apply the family reunification procedures agreed on in advance.

Use flashlights or other safe emergency lighting systems.

Take extra precautions with:

Candles,

open flames,

generators,

fuels,

damaged electrical installations.

During a crisis, old photographs, videos of other volcanoes, audio with no identifiable source, and false evacuation orders can circulate.

Before sharing information, verify that it comes from:

• Official monitoring agencies,
• civil protection authorities,
• emergency services,
• competent government authorities.

Even if ashfall decreases, a visible eruption column disappears, or the activity seems to have ended, do not return to an evacuated area until the authorities allow it.

The following may persist:

New eruptive episodes,

lahars,

gases,

fires,

unstable structures,

damaged roads,

fallen power lines,

water contamination,

other secondary hazards.

During a volcanic emergency, decisions must be based on the specific threat, location, and official instructions, not solely on the volcano’s appearance.

And, most importantly: