Supplementary Material (Carbon tetrachloride content of chlorine-bleach-containing household products and implications for their use)

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Carbon tetrachloride content of chlorine-
bleach-containing household products and
implications for their use
Mustafa Odabasi 1, Tolga Elbir 1, Yetkin Dumanoglu 1, Sait C. Sofuoglu 2
1 Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University,
Tinaztepe Campus, 35160 Buca, Izmir, Turkey
2 Department of Chemical Engineering, Izmir Institute of Technology, 35430 Gulbahce-Urla, Izmir, Turkey
Workshop on "Solving the Mystery of Carbon Tetrachloride“, Zurich, 5-6 October, 2015
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Introduction
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It was recently shown that substantial amounts of carbon tetrachloride (CCl4)
is formed in chlorine-bleach-containing household products as a result of
reactions of sodium hypochlorite with organic product components.
Use of these household products results in elevated indoor air CCl4
concentrations and emissions into the atmosphere.
The objectives of this study were:
(1) to determine CCl4 concentrations in several chlorine-bleach-containing
household products sold in Europe and North America,
(2) to estimate the indoor air concentrations from the use of these products,
(3) to predict CCl4 emissions into the atmosphere from the use of bleach
products.

Materials and Methods
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Forty two chlorine-bleach-containing household products (plain,
n=9; fragranced, n=4; and surfactant-added, n=29) sold in Europe
and North America were analyzed.
The types and commonly used components (declared by the
manufacturers) of the products covered in the present study
were:
Plain (sodium hypochlorite)
Fragranced (sodium hypochlorite, fragrance, inorganic additives)
Surfactant-added (sodium hypochlorite, organic and inorganic
additives, surfactants)
Sampled and analyzed bleach products

Sample Preparation
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For CCl4 analysis, bleach samples were diluted 1/500 times with pre-
purged deionized water containing antifoaming agents and ascorbic acid.
Tablets consisting of sodium sulfate (0.97 g) and silicone (0.03 g) were
used as antifoaming agent while ascorbic acid (0.65 g) was used to quench
the residual chlorine prior to analysis.
Analysis
 Samples were analyzed using a gas chromatograph (GC) (Agilent 6890N)
equipped with a mass selective detector (Agilent 5973 inert MSD, USA) and a
Purge and Trap sampler (Eclipse 4660, OI Analytical, USA).
 The MSD was run in simultaneous scan and selected ion monitoring modes.
 Several other product components (i.e., oxygenated VOCs, hydrocarbons,
chlorine content, trace elements, total organic carbon) were also analyzed.

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RESULTS
 CCl4 concentrations ranged
between 0.01 and 169 mg/L (23.2 ±
44.3 mg/L, average ± SD).
 Concentrations were the lowest in
plain bleach, slightly higher in
fragranced products and the highest
in the surfactant-added products.
 CCl4 concentrations were closely
related to some product components
(i.e., oxygenated VOCs,
hydrocarbons, trace elements,
r2=0.987, p<0.01 for step-wise
multiple linear regression).
CCl4 concentrations in household bleach products.
CCl4 content of bleach products
0.1
1.0
10.0
100.0
Plain
Fragranced
Surfactant added
CCl
4
in Bleach products (mg/L)

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 Indoor air CCl4 concentrations (Cair, µg/m3) were predicted from the use of 42
household products during bathroom, kitchen, and hallway cleaning using the
following simple box model:
 where Cb is the background indoor air concentration (µg/m3), Cwp is the CCl4
concentration in the household product used (µg/m3), Vp is the volume of product
used (m3), and Vair is the zone volume (m3).
 It was assumed that all CCl4 content in the product is emitted into the air during the
use and it is mixed within the zone volume.
 Predicted indoor air concentrations from the use of four products were compared to
those measured in a similar study conducted using the same products. Agreement
between the measured and estimated concentrations was very good (m=1.11, r2= 0.96
p<0.01, n=20).
 =+ 



Indoor air CCl4 concentrations

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 Estimated indoor air concentrations ranged between 0.30 and 1124 (82 ± 194, average ±
SD) µg/m3, indicating substantial increases compared to background (0.27 µg/m3).
 Indoor air CCl4 concentrations from surfactant-added products were significantly higher
(p<0.01) than other categories.
Average indoor carbon tetrachloride concentrations from the use of different product categories.
0
1
10
100
1000
Bathroom
Kit chen
Hallway
CCl4Concentration (µg/m3)
Plain Bleach
0
1
10
100
1000
Bathroom
Kit chen
Hallway
CCl
4
Concentration (µg/m
3
)
Fragranced Bleach
0
1
10
100
1000
Bathroom
Kit chen
Hallway
CCl
4
Concentration (µg/m
3
)
Surfactant Added Bleach

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 Majority of CCl4 in chlorine-bleach-containing household products is
emitted to the atmosphere by:
 Indoor-outdoor air exchange,
 Air-water exchange from waste waters.
 Global annual CCl4 emissions from the use of chlorine-bleach-
containing household products were estimated using the concentrations
measured in this study and an average per capita consumption of 1
kg/year.
 Since the shares of product types (i.e., plain or surfactant added)
were not known, emissions were estimated for two extreme cases:
 (1) plain bleach having the minimum CCl4 concentration,
 (2) surfactant-added bleach having the maximum CCl4 concentration.
CCl4 emissions from bleach products

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 For these two cases, global annual CCl4 emissions ranged between 0.06 and 1230 tons.
 CCl4 emissions from 14 European countries with a population of ~600 million and known
country specific per capita household bleach consumptions were also estimated.
 Annual European CCl4 emissions ranged between 0.02 and 493 tons.
 Per capita household bleach consumptions are highly variable, ranging between 0.22-
11.8 kg/year, and generally they are > 3 kg/year.
 This suggests that the global average per capita household bleach consumption may be
higher than 1 kg/year and as a result global CCl4 emissions may be underestimated.
 Although the estimated global emissions are highly uncertain due to lack of detailed
information on product type and usage amounts, the results of the present study indicated
that household chlorine bleach use is an ongoing source of CCl4 emitting appreciable
amounts to the atmosphere.

CONCLUSIONS
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CCl4 concentrations in household bleach ranged between 0.01 and 169
mg/L (23.2 ± 44.3 mg/L, average ± SD) and concentrations were the lowest
in plain bleach, slightly higher in fragranced products and the highest in the
surfactant-added products.
 Model predictions showed that indoor CCl4 concentrations significantly
increase when bleach products are used for cleaning.
Results also indicated that household chlorine-bleach use is an ongoing
source of CCl4 emitting appreciable amounts to the atmosphere.

THANKS FOR YOUR ATTENTION!
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