Workshop on Hydrofluorocarbon
(HFC) Management
Montreal Protocol
Paris, 11-12 July 2014
Janet F. Bornman
Co-Chair, Environmental Effects Assessment Panel
(EEAP) of the Montreal Protocol
Curtin University
Perth, Western Australia 6845
Janet.Bornman@Curtin.edu.au
1
The effect of HFC and HCFCs
on the biosphere
Hydrochlorofluorocarbons (HCFCs)
Ozone Depleting Substances (ODS)
Greenhouse Gases (GHGs)
Hydrofluorocarbons (HFC)
Greenhouse Gases (GHGs)
Do they have an effect on the biosphere?
2
The effect of HFC and HCFCs
on the biosphere
Levels of complexity
UV radiation, ozone, climate, health, environment
UV-generated hydroxyl radicals (OH), determine the
atmospheric lifetime of climate-relevant compounds
including:
HFCs, HCFCs, CO, NOx, and SO2, methane ….
HCFCs enter the body by inhalation of air, or by skin
contact: breathing difficulties, skin irritation, may
affect other internal organs
3
Air quality and UV radiation
UV
NOx
Ground-level
O3, aerosols
Volatile organic
compounds
Premature mortality (annual, global)
~1.5 million from particulate matter (sulfate, nitrate, most organic
aerosols)
~0.5 million from O3 (OECD, 2013)
Agricultural losses of $12-21 billion (Avnery et al., 2011)
Complex sensitivity to UV radiation and climate
Ozone and climate implications
Documented:
Effects of decreased O3 and increased UV radiation
Not yet well documented:
How will the environment/biosphere be affected by
increased O3 and decreased UV radiation?
And how will climate interactions modify the response?
Predicted likely decrease in tropospheric OH
Lower OH implies slower removal of many important gases:
HFCs, HCFCs, other VOCs, methane, NOx, SO2
5
The effect of HFC and HCFCs on
the biosphere
Trifluoroacetic acid (TFA), a breakdown product of
HCFCs and HFCs in the atmosphere
Readily deposits to the Earth’s surface through dry and
wet deposition
Some of the new hydrofluoroolefins (HFO, unsaturated
HFCs) as replacements for HFCs can lead to increases
in TFA (HFO
TFA)
6
TFA -
Environments at risk
• Strong acid,
forms salts with
minerals in soil
HFCs, HFOs, and HCFCs
CF3-CXyH
O
O
CF3-C-OH
Salt lakes with
no outflow, loss
by evaporation
only
CF2Cl-C-OH
TFA
Microbiological
degradation in
soil and water
7
• Concentrations
in flowing water
are small
• Accumulation
will occur in salt
lakes, playas
and in the
ocean
The effect of HFC and HCFCs on
the biosphere
Trifluoroacetic acid (TFA)
Phytotoxic - negative effects on plant growth
But concentrations not sufficient for observed effects
8
TFA and TCA
Length of watermilfoil (cm)
35
30
25
Control
100 μg/L
1,000 μg/L
30,00 μg/L
10,000 μg/L
Control
20
15
No significant effects
on plants, even at
high concentrations
10
5
0
-10
0
10
20
30
Time (days)
9
40
50
60
The effect of HFC and HCFCs on
the biosphere
Trifluoroacetic acid (TFA)
Phytotoxic - negative effects on plant growth
But concentrations not sufficient for observed effects
Anthropogenic sources
Atmospheric degradation of some HCFC and HFCs
Atmospheric degradation of narcotics
Trifluoromethyl containing pesticides, aluminum production
10
Approximate concentrations of TFA
•Switzerland, Fresh water lakes, springs, rivers: ca 100 ng/L
•USA, Fresh water lakes, springs, rivers: 20 – 140 ng/L
•Europe, Rain water: 0 - 1.5 µg/L
•Oceans: 10 – 200 ng/L
Depositions of TFA largest during the growing seasons
11
Summary
• HCFC has potential negative health effects
• TFA is not bioaccumulative
• Risks to mammals, including humans, aquatic and terrestrial
organisms: negligible
• TFA sources (natural and anthropogenic) and cycling
through the biosphere should be considered for their
environmental impacts
• Continuing monitoring of TFA in the environment may be
required if HFOs are significantly increased to replace HFCs
12
Summary
WMO Assessment of Ozone Depletion (2007):
“TFA from the degradation of HCFCs and HFCs will
not result in environmental concentrations capable
of significant ecosystem damage.”
13