Ecological Properties of  HFCs

Ecological Properties of  HFCs

 Compiled by Rolando Delgado Castillo

 

   Versión en Español                                                               English version

 


HFC-32 (difluoromethane)

The octanol/water partition coefficient suggests a low potential for bioaccumulation and there is low risk to the aquatic environment.

 

HFC-134a (1, 1, 1,2-tetrafluoroethane)

Tetrafluoroethane, when released to the environment, partitions almost exclusively into the atmosphere. Degradation of tetrafluoroethane will occur mainly in the troposphere by reaction with hydroxyl radicals leading to trifluoroacetic acid, formic acid, hydrofluoric acid and carbon dioxide as ultimate degradation products. The overall atmospheric lifetime is 14 years. Tetrafluoroethane has a Global Warming Potential (GWP) of 1300 relative to CO2 at 100 years.

Ecotoxicological properties

Environmental testing of tetrafluoroethane has only been carried out on aquatic organisms. As tetrafluoroethane is a gas special procedures were employed to obtain solutions of the test substance and to prevent losses occurring during the test. All exposure concentrations were analytically verified.

   

HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane)

Mobility
Air, Henry's law : 2645 kPa.m³/mol
Constant (H) ca Result: considerable volatility
Conditions: 20°C /calculated value

Soil/sediments, adsorption : log KOC ca. 2.2
Conditions: calculated value

Abiotic degradation
Air, indirect photo-oxidation : t ½ ca.
25 year(s)
Conditions: sensitizer: OH radicals

Air, photolysis, ODP : = 0
Result: no effect on stratospheric ozone

Air, greenhouse effect, GWP : = 2900
Reference value for C
O2 = 1 at 100 year

Biotic degradation
Aerobic, test : ready biodegradability/closed bottle
Degradation = 20 %, 28 day(s)
Result: non-readily biodegradable

Potential for bioaccumulation
Bioconcentration : log P o/w ca. 2.5
Result: weak bioaccumulation potential
Conditions: calculated value

Comments : Product is persistent in air
(atmospheric lifetime: 36.5 years)
Product is not significantly hazardous for the aquatic
environment as:
· Considerable volatility
· Low bioaccumulation potential

Ecotoxicological properties

Fishes, Brachidanio rerio, LC 50, 96 h >= 30 mg/l
Bacteria, EC 0, activity inhibition : >= 173 mg/l

 

HFC-365mfc (1,1,1,3,3-pentafluorobutane)

 

Mobility
Air, Henry's law constant (H) ca : 3.8 kPa.m³/mol
Result: considerable volatility
Conditions: 20°C /calculated value

Soil/sediments, adsorption : log KOC ca. 1.8
Conditions: calculated value

Abiotic degradation
Air, indirect photo-oxidation : t ½ ca.7.04 year(s)

Air, photolysis, ODP : = 0
Result: no effect on stratospheric ozone
Reference value for CFC 11: ODP = 1

Air, greenhouse effect, GWP : = 890
Reference value for CO2 = 9.9 years

Biotic degradation
Aerobic, test : ready biodegradability/closed bottle, 13 %, 28 day(s)
Result: non-readily biodegradable

Potential for bioaccumulation
Bioconcentration : log P o/w ca. 1.61
Result: improbable bioaccumulation
Conditions: measured value

Comments : Product is persistent in air
(atmospheric lifetime: 1 at 100 years)
Hazard for the aquatic environment is limited due to
product properties:
· Considerable volatility
· Low bioaccumulation potential

Ecotoxicological properties

Acute ecotoxicity
Fishes, Brachidanio rerio, LC 50, 96 h >= 200 mg/l
Crustaceans, Daphnia magna, NOEC, 48 h > 200 mg/l
Algae, Selenastrum capricornutum, NOEC 72 h = 113 mg/l

 

HFC-43-10-mee (1,1,1,2,2,3,4,5,5,5-decafluoropentane)

Mobility
Air, Henry's law : 15 kPa.m³/mol
constant (H) ca Result: considerable volatility
Conditions: 20°C /calculated value

Water, evaporation : t ½ = 3 hour(s)
Conditions: calculated value from mathematical
model/river

Soil/sediments, adsorption : log KOC from 1.6 - 2
Conditions: calculated value

Abiotic degradation
Air, indirect photo-oxidation : t ½ ca. 15 year(s)
Conditions : Sensitizer: OH radicals
Degradation's products :Carbon dioxide / hydrofluoric

Air, photolysis : ODP = 0
Reference value for CFC 11: ODP = 1

Air, greenhouse effect, GWP : = 1300
Reference value for CO2 for 100 years

Water/soil, hydrolysis : t ½ > 10,000 year(s)
Result: non-significant hydrolysis
Conditions: calculated value

Biotic degradation
Aerobic, test : ready biodegradability / modified STURM
Degradation = 5 %, 28 day(s)
Result: non-readily biodegradable

Potential for bioaccumulation
Bioconcentration : aquatic organisms, BCF = 42
Result: non-bioaccumulable
Conditions: calculated value

Comments : Product is persistent in air
(atmospheric lifetime: 17,1 years)
Product is not significantly hazardous for the aquatic environment as:
· Low toxicity for aquatic organisms
· Considerable volatility
· No bioaccumulation

 

Ecotoxicological properties

96 hour LC50, fathead minnows : 27.2 mg/l
96 hour LC50, rainbow trout : 13.9 mg/l
48 hour LC50, Daphnia magna : 11.7 mg/l

Fish, Poecilia reticulata, LC 50, 96 h: 220 mg/l
Crustaceans, Daphnia magna, EC 50, 48 h: 160 mg/l

 

Source: European Fluorocarbons Technical Committee, 2001

http://www.fluorocarbons.org/en/families/hfcs/environment.html

 


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