Ep301: Where There’s Smoke There’s Fire

In this first episode of eleven in season 3, we explore fire- both house fires and wildfires, and dive deep into the science of smoke detectors, flame retardants, how fires spread and how they can be managed.

Featured researchers and experts:
Jay Fleming - Boston Fire Chief, Retired
Michael Link - Analytical Chemist, NIST
Shawn Richardson - House Fire Survivor
Anne Cope - Chief Engineer, IBHS
Ethan Foote - Asst. Fire Chief, Retired
Liora Mael - Atmospheric Chemist, CSU
Yana Valachovic - Wildfire Researcher
Nathan Trauernicht - Fire Chief, UC Davis
Todd Lando - Wildfire Mitigation Specialist, CA
Sarah Henderson - Indoor Air Researcher, British Columbia Centers for Disease Control
Arthur Chan - Environmental Chemist, University of Toronto
Andrew Whelton - Water Safety Researcher, Purdue University
Joseph Wartman - Disaster Resilience Researcher, University of Washington
Miriam Diamond - Environmental Chemist, University of Toronto

Also featuring Vulcan Vents, the IBHS research center, the UC Davis fire department, and lots of footage courtesy of Creative Commons and the US DOD. The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement.

DIVE DEEPER WITH THESE RESOURCES:

TRANSCRIPT:

01;00;01;14

- [Speaker] Things

are moving quicker

01;00;02;12

than they ever have before.

01;00;03;24

- [Speaker] In our

culture, we accept fires.

01;00;05;08

- As the number of

people dying per fire

01;00;07;11

didn't change over 40 years,

01;00;09;05

why didn't that

set off red lights?

01;00;10;26

- [Homeowner] Do we

need a fireproof home?

01;00;12;09

- You know, it's not the way

01;00;13;09

I would go about

doing a remodel,

01;00;14;20

but it's it's an upside.

01;00;17;01

- [Narrator] "Home

Diagnosis" is made possible

01;00;18;20

by support from Broan NuTone.

01;00;20;28

Better air, better life.

01;00;23;16

By the Got Mold? test kit.

01;00;25;19

Real science, real simple.

01;00;27;27

By AirCycler, Retrotec,

01;00;30;10

Rockwool, and RenewAire.

01;00;33;06

By generous support

from these underwriters,

01;00;36;02

and by viewers like you.

01;00;39;19

(bell chimes)

01;00;43;17

- [Announcer] Please standby

for further instructions.

01;00;47;15

- 21 flights of stairs.

01;00;50;04

(intercom chimes)

01;00;51;22

- [Announcer] The fire

trucks have arrived.

01;00;54;04

Please standby for

further instructions.

01;00;57;16

- [Producer] You might

as well just go down-

01;00;58;15

- Yeah, let's just keep going,

01;00;59;23

'cause you can't

open these doors.

01;01;01;14

(intercom chiming)

01;01;03;10

We gotta go down to the

bottom door, anyway.

01;01;07;14

- That is one way to be woken

up at 3:30 in the morning.

01;01;10;07

- But we have our big camera,

01;01;12;08

we have all of our footage.

01;01;15;03

So, worst case scenario.

01;01;17;07

- It was a false alarm.

01;01;18;21

This happened three

nights ago, apparently.

01;01;21;21

Accidents happen.

01;01;23;10

(somber music)

01;01;26;11

- [Narrator] It's

the shields we build.

01;01;33;26

And the risks we take.

01;01;39;26

It's the disasters

that will test us,

01;01;46;10

and what will grow from them.

01;01;51;19

It's real life.

01;01;55;12

And the physics,

chemistry, and microbiology

01;01;58;14

of the science of homes.

01;02;00;18

(somber music continues)

01;02;10;07

- Welcome back to

"Home Diagnosis."

01;02;12;16

- Over the past two seasons,

01;02;14;02

we've learned so

much about the latest

01;02;16;09

indoor physics, chemistry,

and microbiology research

01;02;19;02

that our brains exploded.

01;02;20;13

- And at the same time,

01;02;21;26

the number of extreme

weather and pollution events

01;02;24;08

has also exploded, reaching

right inside our homes.

01;02;28;02

- So, let's examine

the science of homes

01;02;30;10

from the lens of disasters,

01;02;32;11

on this show that's always

been a little bit different.

01;02;35;01

- Everybody watches these TV

shows where, let's face it,

01;02;38;21

to have a good TV fire,

01;02;40;10

you have to show the firemen

crawling through the room,

01;02;42;18

and maybe two or three

pieces of furniture on fire,

01;02;44;20

and they put the fire out,

or they save the baby.

01;02;46;17

That's not the way it works.

01;02;48;03

When you wake up, the

house is filled with smoke.

01;02;51;26

When you have smoke,

particularly from

synthetic materials,

01;02;54;07

it's irritating to your eyes.

01;02;55;27

So the key point in the fire,

01;02;57;18

obviously, it's

important when you die,

01;02;59;22

but the really key point

01;03;01;00

that we have to

change, or affect

01;03;02;22

is when you're trapped,

when you stop moving.

01;03;05;12

If you stop moving, you

will eventually die,

01;03;07;14

unless the firefighter

comes to rescue you.

01;03;09;18

They did these scenario

studies that say,

01;03;11;10

let's look at the way

people are dying in fires,

01;03;13;02

and see where the smoke

detectors can help.

01;03;15;10

According to the US

Fire Administration,

01;03;16;23

and the NFDA, both collect

statistics on this,

01;03;19;10

about 40% of the

people who die in fires

01;03;21;15

die with a working

smoke detector.

01;03;23;02

It was documented by the

chief to have operated.

01;03;25;21

About 40% die when

it's not there at all,

01;03;28;11

and 20% die when

it's been disabled.

01;03;30;22

When I ask people to

guess how many people die

01;03;33;04

with a working smoke detector,

01;03;34;15

they always guess

something like five or 10%.

01;03;36;05

I think they'd be shocked

to find out that it's 40%.

01;03;38;21

That number, according to

the US Fire Administration,

01;03;42;01

like in the late

'80s, was around 20%.

01;03;44;23

And I think sometimes

that's a case

01;03;46;09

of the detector operating,

but operating too late.

01;03;48;16

Think about this, from the

time they started collecting it

01;03;50;28

in say 1980 to today,

fires are down by half,

01;03;55;19

and fire deaths are down

by half, approximately.

01;03;57;28

But actually, the death

per 100 fires is higher now

01;04;03;18

than it was before.

01;04;05;03

So you're telling me that

from a time when only like,

01;04;08;13

say 20% of the country

had smoke detectors

01;04;10;15

to a time when 90% of the

country has smoke detectors,

01;04;14;18

the number of people dying

per 100 fires hasn't changed?

01;04;17;09

That makes no sense,

unless something's wrong.

01;04;20;09

As the number of

people dying per fire

01;04;22;13

didn't change over 40 years,

01;04;24;05

why didn't that set off

red lights, and sirens,

01;04;26;20

and say, stop everything?

01;04;28;01

Let's reconsider

everything we're doing.

01;04;29;27

What are we doing wrong?

01;04;31;21

- So Shawn, we're in your home.

01;04;32;29

#NAME?

01;04;33;27

#NAME?

01;04;35;29

#NAME?

01;04;36;29

It took the length of time

01;04;38;25

a person can grill

a turkey sandwich

01;04;41;01

for the smoke

detector to go off.

01;04;43;11

The stove was here, I was

grilling the sandwich,

01;04;46;13

there was a dog begging

for the sandwich,

01;04;48;22

and I did what you normally do

01;04;50;24

when you're grilling something,

01;04;52;06

and your smoke

detector goes off,

01;04;53;22

which is assume

nothing is wrong.

01;04;57;00

- When I've been using my stove,

01;04;58;20

it's commonly triggered

my smoke alarm

01;05;01;19

without real visible smoke.

01;05;04;06

And so, it's constantly

a question every

day that I go home,

01;05;06;29

like, what am I

exposing myself to?

01;05;09;12

What types of gases, and what

types of particles in the air

01;05;11;27

that I can't see am

I exposing myself to

01;05;14;03

that's making my throat hurt,

01;05;15;27

that's making me wonder

for months do I have COVID?

01;05;20;24

- So, there were two

kinds of detectors,

01;05;22;18

and there's also two kinds

of smoke, to simplify it.

01;05;25;23

In flaming fires, they tend

to give off small particles.

01;05;29;08

Studies have shown that

the ionization detector,

01;05;31;13

because of the way it works,

01;05;32;20

is very sensitive to say,

01;05;34;29

particles less than

one to two microns.

01;05;38;21

The photoelectric is better

01;05;40;23

at detecting the

smoldering fire,

01;05;42;17

which gives off larger particles

01;05;44;03

because of incomplete

combustion.

01;05;45;18

So, almost everyone's asleep

during a smoldering fire.

01;05;47;29

That's when you need

the smoke detector,

01;05;49;17

and several studies as

far back as 1980 in LA

01;05;52;27

showed that sometimes

the ionization

01;05;55;14

may not go off early enough for

you to get out of the house.

01;05;58;07

NIST did a massive

study, which is online.

01;06;00;12

People can check this out.

01;06;01;22

The NIST Home

Smoke Alarm Report.

01;06;03;05

And in that report, in

the smoldering fires,

01;06;05;11

the photoelectrics

on average, I think,

01;06;06;26

responded about 30 minutes

before the ionization.

01;06;09;17

Now that in and of

itself is not bad.

01;06;11;24

If they were responding

30 minutes earlier,

01;06;14;04

but the ionization

was still giving say,

01;06;15;26

five minutes warning

to get outta the house,

01;06;17;08

I wouldn't care.

01;06;18;14

But many of the

fire tests they ran,

01;06;19;21

the ionization was

going off too late,

01;06;21;17

meaning the smoke was too

thick to get outta the house.

01;06;24;11

If you could reduce the disabled

detector deaths by half,

01;06;27;07

that'd be a 10% reduction.

01;06;28;26

If you could reduce

the people dying

01;06;30;16

with a working detector

by half, that's 20%.

01;06;32;27

So, if you reduced fire

deaths in this country by 30%

01;06;36;23

over the last 20 years,

that's a lot of people.

01;06;40;01

- Wow, so great that

your family was not here.

01;06;42;29

- Yes, it could have

been so much worse.

01;06;47;20

Could've been so much

worse, so one of the things

01;06;50;13

that the restoration

company has to do

01;06;52;04

is bring everything up to code

that is currently not code,

01;06;54;24

and there were

several things done

01;06;56;18

by the previous homeowner

that weren't up to code.

01;06;59;09

- The building codes

haven't caught up.

01;07;01;23

For example, you have fire

resistant construction.

01;07;04;23

We're not trying to

prevent all house fires,

01;07;07;14

but it allows for fire

to happen in a building,

01;07;10;10

and contain the fire to one room

01;07;13;15

for either one or two hours.

01;07;15;01

Completely different than

the interface fire problem

01;07;18;15

where it's not containing

the fire that is the goal.

01;07;21;27

The goal is to prevent ignition

of the building at all.

01;07;24;29

Obviously, one method that

we're most comfortable with

01;07;28;07

is building code requirements.

01;07;29;26

You have to do it

this way, or that way.

01;07;31;29

And the other prime driver

01;07;33;09

is gonna be the

insurance companies.

01;07;35;07

And, unlike Europe,

01;07;36;26

they're not gonna be

providing discounts.

01;07;38;27

They're on the road towards

understanding the problem

01;07;41;24

well enough that they can

make very strict requirements,

01;07;45;07

and regardless of what

the government recommends,

01;07;48;14

or what the codes require,

you can't get insurance

01;07;51;19

without complying

with their standards.

01;07;53;23

The insurance pressure is

coming, not in incentives,

01;07;57;05

but in denying coverage.

01;08;00;16

- [Narrator] Big city fires

01;08;01;23

have always gotten

a lot of attention,

01;08;03;24

with wildfires being

largely ignored.

01;08;06;09

Take, for example, the

Great Chicago fire of 1871.

01;08;10;10

We all know that one.

01;08;11;26

You probably didn't know that

across the border in Wisconsin

01;08;15;13

on the exact same night,

the Peshtigo Wildfire

01;08;19;17

killed over 1,500 people.

01;08;22;03

It's still the most

deadly fire in US history.

01;08;26;13

#NAME?

01;08;28;14

that can quickly

become a disaster.

01;08;31;08

- And once we've observed

a hazard like fire

01;08;33;29

enough times, and

in enough detail,

01;08;36;02

then researchers can

build experimental labs

01;08;38;15

like the one behind us, so

that we can simulate it.

01;08;41;11

- Yeah, and what they're doing

in this experimental lab,

01;08;43;06

and lots of experimental

labs all over,

01;08;45;17

which you're gonna see lots of

01;08;46;25

in this season of

"Home Diagnosis,"

01;08;48;10

is testing systems and products

01;08;50;02

to see if they work in

making a home safer.

01;08;52;19

- So that we can

keep those hazards

01;08;53;27

from turning into disasters.

01;08;55;20

Let's go inside.

01;08;59;07

- [Researcher] The biggest

thing that we research here

01;09;01;29

is how do the embers

get carried by the wind

01;09;05;06

all around the structure there,

01;09;06;23

and interact with it in a

realistic wind environment?

01;09;09;28

That's really important

for us to study.

01;09;11;26

- It's a complicated name.

01;09;13;17

It's called the Wildland-Urban

Interface Fire Problem.

01;09;17;05

At its most basic

level, it can be defined

01;09;19;21

by three elements that

happen very quickly.

01;09;22;29

First, the fuel feeding a fire

01;09;25;05

changes from vegetation to

buildings, hence wildland-urban.

01;09;30;13

So many houses ignite so quickly

01;09;33;19

that the fire department

is overwhelmed.

01;09;36;17

During these disastrous

interface fires,

01;09;39;09

90% of the buildings are

destroyed once they are ignited.

01;09;42;07

So once they're ignited,

nine times outta 10,

01;09;44;22

the building's on the

ground, completely.

01;09;46;24

- About 60 to 90% of

the home ignitions

01;09;49;19

during wildfires happen

from the tiny embers

01;09;52;04

that are generated by the fire.

01;09;53;17

They blow ahead of the fire,

01;09;55;06

carried by the

heat, and the winds

01;09;57;03

that drive fires typically.

01;09;58;25

Houses can also ignite

from direct flame exposure

01;10;01;27

if flames can reach out and

touch the building materials,

01;10;04;26

ignite the building

materials directly.

01;10;07;01

And then, in some

cases, radiant heat.

01;10;09;13

And that's like the, you know,

01;10;10;19

the heat that you

feel from a campfire.

01;10;12;14

If there's enough of it, it

can actually ignite surfaces.

01;10;15;22

- There's three things that

people should really think about

01;10;18;05

in terms of vulnerabilities

of your home.

01;10;19;29

First and foremost, the roof.

01;10;22;08

You wanna have a class A roof,

and you wanna keep it clear,

01;10;25;01

because that ember lands on

top of a bunch of pine needles,

01;10;28;20

or something like that,

01;10;29;27

now you've got a

much bigger fire.

01;10;31;21

The Paradise fire, you

know, a lot of pine trees,

01;10;35;00

oak trees, and we saw

a lot of gutter fires,

01;10;38;07

because that material was

deposited in the gutters.

01;10;41;12

Then we had penetration

underneath the roof planes,

01;10;44;00

because of gutter fires.

01;10;45;08

Basically, the town

of Paradise was burned

01;10;47;05

in a six hour time period,

with a continuous wind,

01;10;50;14

and with resources

basically dedicated

01;10;53;02

solely to getting people

out of harm's way.

01;10;55;24

What we found as the strongest

predictor of failure,

01;10;59;12

or loss of an

individual building,

01;11;01;06

was the distance to the

nearest lost structure.

01;11;05;04

Meaning that if your structure

01;11;06;18

was within 50 feet of

another lost structure,

01;11;09;17

the likelihood of

failure was very high.

01;11;12;08

#NAME?

01;11;14;11

Roof vents, crawl space vents.

01;11;16;26

You want those to not allow

large embers to penetrate.

01;11;20;18

- So, a top priority

is to create a shield

01;11;23;26

to keep out embers and flames

01;11;25;24

from vented attics

and crawl spaces.

01;11;28;24

Kids, do not play with

fire without your parents,

01;11;31;23

and you're awesome for

watching this channel.

01;11;33;24

- A huge advance in the

fire safe technology here

01;11;36;08

is intumescent coatings,

01;11;38;11

which work something

like a bulletproof vest.

01;11;40;16

They don't sag away

from the heat of flames,

01;11;42;19

they actually swell up

and create a firewall

01;11;45;09

if the wildfires flames get

close enough to the house,

01;11;48;03

which we hope doesn't happen.

01;11;50;05

- And then third,

critical defensible space.

01;11;54;10

The wind interacts

with normal size homes

01;11;57;20

such that it creates

an eddy at the bottom

01;12;00;23

that's about five feet.

01;12;02;29

So five feet from the wind,

five feet from the heat,

01;12;05;29

from something burning

next to the home.

01;12;07;25

- And if you're sitting

inside your living room,

01;12;09;26

or your kitchen, you

can now see the flowers,

01;12;12;04

as opposed to only seeing it

when you drive up to the house.

01;12;15;04

Planting groups are in islands,

01;12;16;24

they're not connected

to other groups,

01;12;18;12

there's not combustible

mulch between it all.

01;12;21;14

They're separated

from the house.

01;12;23;08

The trees are limbed and pruned,

01;12;25;01

and I think it can

be very beautiful.

01;12;26;21

It's just about looking at

it a little bit differently.

01;12;29;28

- The buildings that survive

these interface fire disasters

01;12;33;07

survive by not igniting,

01;12;36;03

or having very

limited ignitions.

01;12;38;10

So, after cleaning,

the homeowners

01;12;41;05

go right back into their houses.

01;12;44;09

#NAME?

01;12;46;04

The wildfire program

can feel heavy,

01;12;48;14

especially when you

try to think of it

01;12;50;01

in finding a finite solution.

01;12;52;19

Even taking a small step today,

01;12;54;17

even if you can't do everything

01;12;56;27

to make your home fire

resilient, fire adaptive,

01;13;00;15

any steps are good steps

01;13;02;24

towards creating

that safer community.

01;13;05;21

- On the flip side,

wildfire can be quite good.

01;13;08;24

Many of our ecosystems

are adapted,

01;13;10;29

or dependent upon wildfire.

01;13;13;05

There's a lot of good fire

doing good work out there.

01;13;15;17

We're never gonna stop it.

01;13;17;20

We just have to figure out

how we learn to live with it,

01;13;19;26

how we can mitigate some

of its damaging effects,

01;13;22;04

and how we can enhance some

of its positive effects.

01;13;25;05

I think that will

be the success.

01;13;27;12

- You know, when I

talk to foresters,

01;13;28;28

they often talk about

good fire, and bad fire.

01;13;32;02

Where good fire is

controlled, prescribed fire,

01;13;35;13

and bad fire is wildfire.

01;13;37;19

There's no such thing as

good smoke, and bad smoke.

01;13;40;06

There's maybe less

smoke, and more smoke,

01;13;42;22

but all smoke from

burning on the landscape

01;13;46;14

is harmful to human health.

01;13;48;21

Hopefully, when you're

doing prescribed burning,

01;13;51;06

the conditions are favorable,

01;13;53;17

and that burn is not

gonna get out of control.

01;13;57;14

And it does mean that it

tends to happen in cooler,

01;14;00;14

slightly wetter weather.

01;14;02;07

It also is amenable to what

we call smoldering fire

01;14;07;05

versus flaming fires.

01;14;09;09

So, different stages of

the combustion process.

01;14;12;16

And smoldering fire

does create more smoke,

01;14;15;29

because the combustion

is less complete

01;14;19;00

than during a flaming fire.

01;14;21;14

There's quite a

lot of evidence now

01;14;23;20

to show that on

a per mass basis,

01;14;27;27

the smoke from smoldering

fire is more toxic

01;14;31;26

than the smoke

from flaming fire.

01;14;34;05

It has a lot more

different stuff in it,

01;14;37;05

whereas the smoke

from flaming fire

01;14;39;06

is more elemental carbon.

01;14;42;24

- An analogy can be made between

the interface fire problem

01;14;46;01

and the high-rise fire problem.

01;14;48;00

You can't evacuate

everyone at the same time

01;14;50;29

in a lot of these buildings,

01;14;52;07

and so you have what are

called fire refuge areas

01;14;54;28

in high rise buildings,

01;14;56;12

especially for people

with mobility challenges.

01;14;59;11

So there needs to be communities

01;15;01;15

with two ways in, two ways out,

01;15;03;15

and the ability for

fire apparatus to

get into a community

01;15;07;08

while the whole community's

trying to evacuate,

01;15;09;17

but also look at

sheltering in place,

01;15;11;29

which is a concept

that the Australians

01;15;14;11

have had years of

experience with,

01;15;16;24

and developing

fire refuge areas.

01;15;20;17

- There are many facets

to the wildfire problem.

01;15;22;16

We need to turn the

dials on all of them.

01;15;24;15

The emergency alert system,

01;15;25;29

the evacuation system,

where and how we build.

01;15;28;22

How do we protect critical

infrastructure, you know?

01;15;30;27

Our water supplies,

our hospitals, schools,

and facilities,

01;15;34;05

they all need special help.

01;15;35;25

And how do we choose

where and how to live?

01;15;39;20

- So when I first

moved to Fort Collins,

01;15;41;14

it was the day of

the Marshall Fires.

01;15;43;26

We had a 100 mile

per hour winds,

01;15;45;29

and the apartment I was

supposed to move into

01;15;48;24

was in the line of fire.

01;15;50;29

I took a duffel bag

of stuff outta my car,

01;15;52;28

moved my animals in,

01;15;53;26

and then we had to evacuate.

01;15;55;14

You know, coming back,

and there's nothing there.

01;15;57;19

There were like, you

know, shells of a car,

01;16;00;19

or just someone's

fireplace still standing.

01;16;03;03

It was, and then the

next day, it snowed.

01;16;07;19

- The Marshall Fire, a

December 31st, 2021 fire.

01;16;11;29

You'd think it would

be a safe time of year.

01;16;14;02

That fire was

eventually extinguished

01;16;15;24

12 hours later by snowfall.

01;16;17;17

And what we saw there

was a grassland fire,

01;16;20;12

not something where you'd see

01;16;21;16

a lot of ember

movement, necessarily,

01;16;23;14

but grassland connection

to wooden fences,

01;16;26;10

and wooden fences igniting,

01;16;28;09

and then being able

to wick the flames

01;16;30;01

directly to buildings,

and then attached fences

01;16;33;07

then basically burning

adjacent to buildings,

01;16;35;24

and creating an ignition

point inside the building.

01;16;39;03

Every fire burns in a

different fuel type.

01;16;42;19

And these are not

the kinds of embers

01;16;45;07

that will make it

through someone's vent,

01;16;47;13

because they will just

extinguish themselves

01;16;49;06

as they're blowing in the wind.

01;16;51;05

But as you start to get

bigger pieces of fuel,

01;16;53;25

they can burn for a longer time,

01;16;55;14

and they can cause more damage.

01;16;57;06

And so if a two by four

gets picked up and dropped,

01;16;59;29

it's gonna burn for a long time.

01;17;02;08

So all of this matters

01;17;04;16

when we kind of bring

in the fire science,

01;17;06;10

and we are trying to think

01;17;07;08

about the individual product,

01;17;08;26

and how the building

is assembled,

01;17;10;13

and what it's being

asked to resist.

01;17;13;17

- In 2016, there was this major

wildfire in Fort McMurray.

01;17;17;24

I think about 20% of the

homes were destroyed.

01;17;20;06

The local government

agency tested the soils,

01;17;23;13

and they found high

levels of arsenic,

01;17;26;20

and that might stay

in the home in dust,

01;17;28;25

and it could be a cancer risk.

01;17;32;11

In pressure treated wood,

very often the wood is treated

01;17;36;00

with chromium,

copper and arsenic.

01;17;38;10

And when the wood from the

deck, for example, gets burnt,

01;17;42;27

that can release the arsenic

into the environment.

01;17;46;07

So the ash can be pretty

light, it can blow around,

01;17;49;17

and so it could go in

through air exchange

01;17;52;26

like through your window,

01;17;54;02

or through your air

handling system.

01;17;55;27

It could also be

tracked into your shoes,

01;17;57;19

and you can bring

it in that way.

01;17;59;26

I think what we have

learned from our study

01;18;02;27

is it is possible

to clean to a point,

01;18;05;21

wiping down the surfaces,

cleaning off the dust.

01;18;08;07

We would have very

low health risks.

01;18;10;23

However, we did not do our study

immediately after the fire.

01;18;14;25

And so we know very

little about what happens

01;18;18;08

the day that you move back home.

01;18;20;00

So I think in the future, if

we can gain more understanding,

01;18;23;02

then we can give

better advice to people

01;18;25;04

as they are going

back after evacuation.

01;18;28;28

(gentle music)

01;18;32;29

- When a wildfire

enters a community,

01;18;34;16

it starts jumping house to

house, or building to building.

01;18;37;03

And as those buildings burn

down, or are destroyed,

01;18;39;22

they become mini

water fountains,

01;18;42;00

and when we have too

many water fountains,

01;18;44;12

what happens is we don't

have enough water pressure.

01;18;47;15

And so, the water stops

coming outta the houses,

01;18;50;14

and now you have a direct line

01;18;52;19

from the the debris,

or the the vapors,

01;18;55;25

or the smoke, into the

drinking water system,

01;18;58;27

because there are no

backflow prevention devices

01;19;02;09

between the homes, and

the distribution system.

01;19;04;28

Well, during disasters,

what also happens

01;19;07;03

is you lose power, and

you use communications.

01;19;09;17

And so when you

lose communications,

01;19;11;18

you can no longer understand

01;19;13;07

what's happening in

your water system.

01;19;14;25

During the Marshall Fire in

Boulder County, Colorado,

01;19;17;15

they had to physically

get in vehicles,

01;19;20;04

and drive through

the active fire zone,

01;19;22;22

climb up tanks to inspect,

01;19;25;05

to figure out how much

water they had left.

01;19;28;15

The city of Lewisville

almost ran outta water.

01;19;32;02

They made a decision to

bypass the water plant,

01;19;35;20

and send lake

water directly into

01;19;37;28

their distribution

system, right?

01;19;39;21

So the whole concept

of water treatment

01;19;42;03

is we wanna remove

the organisms,

01;19;43;26

remove the chemicals,

and make that water safe.

01;19;46;16

But Lewisville bypassed

the treatment plant,

01;19;49;05

and sent the water

to the firefighters

01;19;51;03

through fire hydrants.

01;19;52;13

If they hadn't done that,

01;19;54;01

you might've seen thousands

of more homes destroyed.

01;19;58;08

East Boulder County

Water District

01;20;00;06

had their natural gas shut off,

01;20;02;04

so they couldn't push

water into their system.

01;20;05;07

Many of their customers

live on a mountain,

01;20;08;19

so the water goes

up the mountain,

01;20;10;06

and when they stopped

pushing water,

01;20;12;03

all that water

drained down the hill.

01;20;14;04

And when they went

back to repair it,

01;20;16;18

they had to open fire

hydrants for two hours,

01;20;19;13

and have air come out,

01;20;21;26

because that's how far

away the water went.

01;20;24;04

So they had to bring it all

the way back up the hill,

01;20;26;18

and that is depressurization,

and contamination.

01;20;30;07

- We're still

trying to figure out

01;20;32;10

exactly what are the mechanisms

01;20;34;22

by which landslides are

triggered after wildfire.

01;20;38;22

There's a couple hypotheses.

01;20;40;23

One is the formation

of what's called

01;20;42;29

hydrophilic elements, or oils.

01;20;45;05

These are essentially oils in

the plant leaves that burn,

01;20;48;13

and are deposited on

the ground surface,

01;20;50;24

and they serve as a waxy barrier

01;20;53;08

that prevents

subsequent rainstorms

01;20;55;26

from infiltrating

into the ground.

01;20;58;13

And in consequence, you

have a big pulse of water

01;21;01;26

that reaches hollows, and

then that big pulse of water

01;21;05;26

can very quickly turn the

ground in those hollow areas

01;21;09;13

into these fast-moving

debris flows.

01;21;12;17

- So when a fire

happens in your home,

01;21;14;18

the other thing that happens

is your home gets flooded.

01;21;17;08

- Yeah.

- So was it a total loss?

01;21;20;08

- It was called a

freestanding loss,

01;21;21;26

which basically means

the amount of damage done

01;21;25;16

exceeded the amount of

coverage covered by the house.

01;21;28;25

My neighbor directly

across the street

01;21;30;20

co-owns a restoration company,

01;21;33;01

said this side of the

house can be saved,

01;21;36;12

cleaned, and repurposed,

01;21;38;08

so that side of the house

01;21;40;02

could be rebuilt from

the foundation up.

01;21;42;03

And that's the only way that

we weren't forced to sell

01;21;45;01

is that he was able

to pull that off.

01;21;49;20

- Flame retardants retard

the combustion process,

01;21;51;27

just like wet wood as

opposed to dry wood.

01;21;53;22

So, they tend to

produce smokier fires.

01;21;57;00

The type of self-contained

breathing apparatus

01;21;58;24

that firefighters wear today

01;22;00;05

really didn't exist

until the late '70s,

01;22;01;25

and very few firefighters

would wear their mask

01;22;03;26

during the '50s, '60s,

and into the '70s.

01;22;06;18

I came on right

at the transition,

01;22;08;04

but we didn't have enough,

01;22;09;26

so as the youngest kid, I had

to wear the old heavy mask,

01;22;12;05

and it weighed about 40 pounds.

01;22;14;08

Well, that's a lot to carry

01;22;15;24

when you're also dragging

hoses, and working tools.

01;22;17;19

So, the older guys, they'd

run to the front door,

01;22;20;04

and if they could smell

that it was a cotton smoke,

01;22;22;06

they'd say, ah, don't worry

about it, let's go in.

01;22;24;04

And if it was, they'd say it's

plastic, put your mask on.

01;22;26;10

And it's sort of fascinating.

01;22;27;22

So like, you have a cigarettes

and furniture problem,

01;22;30;18

and the CPSC says, we're gonna

tell the furniture industry

01;22;33;11

to make furniture that's

resistant to smoldering fires.

01;22;36;18

Good idea.

01;22;37;25

Furniture industry says, okay,

01;22;39;10

the way to do that is to get

rid of the cotton batting

01;22;40;29

and go to polyurethane foam.

01;22;43;10

Okay?

01;22;44;16

Well, the problem

with polyurethane foam

01;22;45;22

is it burns a lot faster

than cotton batting,

01;22;47;27

and so flashover occurs in say,

01;22;49;20

four minutes instead

of eight minutes.

01;22;51;14

So now let's put flame

retardants in the furniture.

01;22;53;18

So, you've solved one

problem, created another.

01;22;56;26

#NAME?

01;22;58;10

They're organic chemicals

that have been added

01;23;00;25

to a wide range of

products and commodities

01;23;04;13

to reduce the flammability

of that product.

01;23;10;25

But I wanna quickly add

that there is scant evidence

01;23;14;25

of the benefits that

flame retardants

01;23;17;26

actually do reduce harm.

01;23;20;13

That is, harm from fires.

01;23;22;02

So, evidence of harm from

exposure to flame retardants.

01;23;28;21

Scant evidence that

flame retardants are

actually effective

01;23;32;00

at reducing harm from fires.

01;23;34;13

#NAME?

01;23;36;27

show that it doesn't

make a difference.

01;23;39;12

The TB117 couch, and the

non-flame retardant couch,

01;23;43;08

when you put a match to them,

01;23;44;15

they basically burn

exactly the same.

01;23;46;11

Why?

01;23;47;08

Because in a real fire,

01;23;49;24

it's not like you're

cutting open the fabric

01;23;52;05

to expose the foam,

01;23;53;17

and then some kid's putting

a match to the foam.

01;23;54;29

That's not what happens.

01;23;56;11

The fabric is catching fire,

01;23;58;08

and by the time it

gets to the foam,

01;24;00;13

it's not a little

flame, it's a big flame,

01;24;02;29

and the test would only stop

burning from a small flame.

01;24;06;13

So in the real world,

01;24;07;23

it didn't make any

difference, probably.

01;24;09;26

As one researcher said,

01;24;11;11

we made a test so

they'd have to put in

01;24;12;28

just enough flame retardants

to give us cancer,

01;24;15;19

but not enough to

stop the fires.

01;24;17;24

What we may have done

01;24;19;05

by adding these chemicals

to the furniture

01;24;20;24

has not necessarily changed

the heat release rate

01;24;23;23

because the test they

were designed to pass

01;24;25;24

didn't mimic real

life conditions.

01;24;27;16

We may have just had

them produce more smoke,

01;24;30;26

and the smoke they did

produce was more irritating,

01;24;33;09

which actually

shortened the time

01;24;35;10

for people to get

outta the house safely.

01;24;37;08

- Most of us spend the vast

majority of our time indoors,

01;24;41;01

at least 90% of our time,

and that's pathetic,

01;24;44;10

but it's also just an

indicator of real life

01;24;48;20

in the modern world.

01;24;50;13

And the indoor environment

can protect us,

01;24;56;09

or it can put us at risk.

01;24;57;07

It can do both of those things.

01;24;59;20

So, the ability to

keep wildfire smoke

01;25;02;25

out of the indoor environment,

01;25;04;15

the ability to keep

the indoor environment

01;25;07;00

at a comfortable,

safe temperature,

01;25;10;05

the ability to keep the

indoor environment dry,

01;25;13;16

all of these risks

that we're facing

01;25;16;10

as the climate changes,

01;25;18;08

we need to be evolving

the indoor environment

01;25;21;25

to keep us safe

from those risks.

01;25;26;10

- The evolution has begun,

whether we like it or not.

01;25;29;19

- Fires are just

the start for us.

01;25;31;24

Over these 11 episodes,

we'll dig deeply

01;25;33;27

into the science of

many other disasters,

01;25;36;09

and how to avoid them.

01;25;38;02

- This season is not

here to scare you,

01;25;40;03

though you may get that feeling.

01;25;41;21

This research will help

you prepare your home

01;25;44;04

for the 21st century.

01;25;45;26

- To learn more

about fire safety,

01;25;47;13

and all the other hazards

we're navigating this season,

01;25;50;10

visit homediagnosis.tv.

01;25;52;21

See you next time.

01;25;54;11

(tense music)

01;25;58;17

(tense music continues)

01;26;18;12

(tense music continues)

01;26;30;21

- [Narrator] "Home

Diagnosis" is made possible

01;26;32;10

by support from Broan NuTone.

01;26;34;17

Better air, better life.

01;26;37;04

By the Got Mold? test kit.

01;26;39;09

Real science, real simple.

01;26;41;16

By AirCycler, RetroTec,

01;26;43;29

Rockwool, and RenewAire.

01;26;47;02

By generous support

from these underwriters,

01;26;49;19

and by viewers like you.