Hazardous Chemicals in PVC Flooring

A report compiled for the Healthy Flooring Network by

Michelle Allsopp, David Santillo and Paul Johnston

Greenpeace Research Laboratories

Universisty of Exeter

EX4 4PS

Greenpeace Research Laboratories Technical Note

N: 14/00, November 29th 2000
Abstract

This study investigated the composition of PVC flooring with respect to certain chemical

additives, namely phthalate plasticisers and organotins. The study included analysis of five PVC

flooring samples that were available for retail in the UK. Samples were found to contain high

levels of several organotin compounds, in particular DBT (37.7 to 569 ppm) and TBT (128 to

17,940 ppb). Two phthalates were also detected at high concentrations. Diisononyl phthalate

(DINP) was found in all samples at levels ranging from 4.7 to 15.8% by weight and butyl

benzyl phthalate (BBP) was present in three samples at levels from 1.6 to 5.0%.

These finding are of concern in relation to the presence of hazardous substances in consumer

products, their potential release to the environment and, in turn, their potential impacts on the

environment and human health. Phthalates and organotins are hazardous chemicals. Organotins

cause toxicity to the immune system in laboratory animals whilst phthalates exhibit a wide

range of toxicity’s. The use of PVC flooring and other household furnishings has generated

concern recently after it was hypothesised that the release to air and particulates of the phthalate

plasticiser di(2-ethylhexyl) phthalate (DEHP), present in PVC interior surfaces, may increase

the risk of childhood asthma. Another study linked exposure to PVC floors in the home with

increases in bronchial obstruction in children, possibly caused by plasticisers. In respect of the

known and suspected toxicity’s of phthalates and organotins and their possible impacts on

human health, the results of this study are of great concern.

INTRODUCTION

PVC (polyvinyl chloride, or vinyl) is currently a very widely used plastic with many

applications including flooring, furniture, window frames, pipes and short-life packaging. The

use of PVC has increased greatly during recent decades and consumption is predicted to

increase still further in the future (see van der Naald and Thorpe 1998). PVC is always

formulated with a range of additives to enhance its properties (Ehrig 1992). Additives for PVC

have included hazardous substances such as lead, cadmium, organotins and phthalate

plasticisers. The use of such additives has generated concern regarding environmental

contamination and human health, in part, because of potential leaching of these additives from

PVC products. For instance, children’s toys made from soft PVC have been shown to contain

10-40% by weight of phthalate plasticisers (Stringer et al. 2000), and an emergency ban has

been ordered by the European Union since December 1999 on the use of certain phthalates in

toys designed to be chewed by children of under three years old (Official Journal of the

European Communities 1999). A permanent ban is under discussion. In addition to concerns

about chemical additives in PVC, there are also concerns about contamination of the

environment by hazardous chemicals during the production of PVC (Stringer 1998), and the

serious waste problems posed by the now perpetually growing mountain of PVC waste (van der

Naald and Thorpe 1998).

The present study was undertaken as part of a wider study on the identification of hazardous

chemicals as additives in carpets and PVC flooring. The intention of the present study was to

identify and quantify levels of chemical additives in PVC flooring, specifically, phthalates and
organotins. PVC is commonly used for the production of flooring for homes because it provides

inexpensive, easy to clean surfaces and is especially practical in kitchens, bathrooms and

children’s playrooms and bedrooms (see Jaakkola et al. 1999). PVC flooring is constructed

from soft PVC that has been plasticised to make it flexible. The most commonly used

plasticisers for manufacturing soft PVC are phthalates (phthalate esters). Historically, diethylhexyl phthalate (DEHP) has been the most commonly used phthalate but and more recently

there appears to be increased market use of di-isononyl phthalate (DINP) (Stringer 2000).

Phthalates do not bind to PVC chemically, but are present as freely mobile and leachable

components of the plastic matrix. Consequently phthalates are gradually lost from PVC over

time by volatilisation to the air (Cadogan et al. 1993). It is however not possible to measure

directly the amount of phthalates emitted from PVC flooring to air using currently available

technologies (Friedberg and Karlsson 1993, Howick 1996). Moreover, the results of such

studies will always be strongly influenced by the particular conditions employed. Phthalates

have a high affinity for particles and a recent study in Norway showed that as well as vaporising

to air, these chemicals were also present in suspended particles in air and in sedimented dust

samples from homes (Oie et al. 1997). The study demonstrated that phthalates migrated from

PVC flooring to sedimented house dust. For PVC floors, washing has also been shown to

release phthalates into the water (Moller et al. 1996).

Human exposure to phthalates in the indoor and outdoor environment occurs via background

contamination of air, food and water. Of these, by far the greatest exposure has been estimated

to occur via food intake (0.25 mg per day or >90%) (US ATSDR 1997). Nevertheless, a recent

study on exposure via air in the indoor environment concluded that exposure through this route

was greater than previously assumed because of the presence of phthalates in suspended

particles in the air and in house dust (Oie et al. 1997). Human exposure to phthalates may also

occur from direct contact with PVC products, for instance, skin contact with the surface of

floors and, in the case of young children, chewing of soft PVC toys (CSTEE 1998). A recent

study in the USA that investigated levels of phthalate metabolites (breakdown products) in urine

concluded that human exposure to phthalates was greater than previously assumed (Blount et al.

2000). Studies on laboratory animals have shown that phthalates exhibit a wide range of toxic

effects (KEMI 1994, US ATSDR 1997). In humans, data on health effects are mainly limited to

a few studies on occupational exposure to phthalates and impacts on health. However, one

recent study (Oie et al. 1997) hypothesised that exposure to the phthalate DEHP in the home,

especially from inhalation of particulate matter containing DEHP, may increase the risk of

inflammation of the lung airways and as a consequence, increase the risk of asthma. The

hypothesis was partly formed on the basis of previous research evidence that mono (2-

ethylhexyl) phthalate (MEHP), which is the major breakdown product of DEHP, was found to

induce bronchial hypersensitivity in rats, and that pre-term human infants exposed to PVC

respiratory tubing systems had a higher risk of bronchial asthma. Recently, a further study in

Norway indicated that PVC flooring may increase the risk of bronchial obstruction in young

children (Jaakkola et al. 1999). Exposure to phthalate plasticisers from surface materials in the

home was hypothesised to be the causal agent.

Regarding organotins, these compounds have been used for a variety of applications following

their discovery and initial use as a moth repellent in the 1920’s (Moore et al. 1991). Organotins,

specifically tributyltin (TBT), has been used on a worldwide basis as an antifouling agent in

paints for boats and ships. Organotins are also used as heat stabilisers in PVC and as biocides in

industry and agriculture. It has recently been reported that the major use of organotins is for the

heat stabilisation of PVC which represents about two-thirds of the global consumption of these

compounds (Sadiki and Williams 1999). Both butyltins and octyltins have been used. The latter
group of compounds were specifically developed in an attempt to overcome toxicity problems

of the generally toxic butyltins (Matthews 1996). Studies on laboratory rodents have shown that

TBT is toxic to the immune system (see e.g. Kergosien and Rice 1998). As a consequence of its

use in paint for marine shipping, TBT has caused major reproductive problems some species of

shellfish and in some instances has been related to massive populations declines (Gibbs 1988,

1993, Bryan et al. 1986, 1987). This has led to national restrictions on its use for shipping and

more recently to a decision for a global phase out for this use by 2008 adopted under the

International Maritime Organisation Assembly Resolution A.895(21). Concern has also been

expressed about the level of intake of TBT from consumption of contaminated fish and shellfish

(Belfroid et al. 2000). A recent study in Germany raised concern about the presence of

comparatively high levels of TBT and other organotins in PVC flooring (Oeko-Test 2000).

Research on organotins has suggested that they leach from PVC under laboratory simulated

landfill conditions (Mersiowsky et al.1999) and from PVC water pipes to water (Sadiki and

Williams 1999).

The intention of the present study was to provide information on the quantity and type of

phthalates and organotins in five PVC flooring samples that were purchased in the UK. The

study was undertaken to provide empirical data on the chemical composition of PVC flooring. It

was not intended to generate data for calculating potential leaching rates of phthalates and

organotins from PVC flooring, or for calculating potential doses that individuals may take from

exposure to PVC flooring in the home and potential consequences for human health.

METHODS

Samples

Five different samples of PVC flooring for analysis (NGP009, NGP010, NGP011, NGP012,

NGP013) were purchased from various retail suppliers in the UK (see table 1).

Table 1. List of PVC Flooring Samples

Sample Number Sample Brand

NGP009 Marley Floors. The Tile Collection, Cushioned

tiles 5 010 941 207 609

NGP010 B & Q plc. Vinyl tiles. Item no. 24408486

Batch no. 0294

NGP011 Gerflor Limited. Classical collection,

Rembrandt with roctop surface, 181 R

NGP012 Armstrong. Rhinofloor, Diamond with

Rhinogloss, 30806

NGP013 Forbo Nairn. Cushionflor, Ultima, Gemini,

35128

Phthalates

Analysis of phthalates was carried out by the Laboratory of the Government Chemist,

Teddington, Middlesex, UK, using a UKAS accredited method, LGC SOP OTH/C1-0015

(details provided on request). The above PVC flooring samples were analysed for six

phthalates, as listed by the EU Scientific Committee on Toxicity, Ecotoxicity and the

Environment (CSTEE), (Di-isononyl phthalate (DINP), Di-ethylhexyl phthalate (DEHP), Di-noctyl phthalate (DnOP), Di-butyl phthalate (DBP), Di-isodecyl phthalate (DIDP), Butyl Benzyl
Phthalate (BBP). The limit of detection for all phthalate compounds tested for was ≤ 0.05 % by

weight. Also tentatively identified was diheptyl phthalate which was co-extracted with the other

phthalates.

Organotins

Organotin analysis was carried out by GALAB, D-21502 Geesthacht, Germany, using an

accredited method (details available on request). The PVC flooring samples were analysed for

organotins (monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), tetrabutyltin,

monooctyltin, dioctyltin, tricyclohexyltin and triphenyltin). The limit of determination was 0.3

μg/kg, limit of detection 0.1 μg/kg, measurement uncertainty 10-20% and recovery 75-100%.

RESULTS

Results of the analysis of 5 PVC flooring samples for phthalates and organotins are presented in

tables 2 and 3 respectively. With regard to phthalates, DINP was found in all of the samples and

BBP was present in three out of the five samples. Given the hazardous nature of these

compounds the levels of DINP and BBP found in the samples are clearly of concern. Diheptyl

phthalate was also detectable in 3 of the samples. All other phthalates that were analysed,

including DEHP, were below the detection limit.

Several organotins were identified as components of all the PVC flooring samples. Dibutlytin

(DBT) compounds are the most commonly used organotin stabilisers in PVC (see Matthews

1996). It was not surprising, therefore that DBT was found to be present at the greatest

concentrations (range 37,700 to 569,000 ppb or 37.7 to 560 ppm).. Levels of TBT were also

high (2,730 to 17,940 ppb) in four out of the five samples. The TBT concentrations in the PVC

flooring samples were similar to those reported by in a recent study on 16 samples of PVC

flooring from Germany (range, not detectable to 3520 ppb) (Oeko-Test 2000), with the

exception of sample NGP009, for which the concentration (17,940 ppb) was nearly an order of

magnitude higher than samples previously tested in Germany.

Table 2. Percentage Concentration by Weight of Phthalates in Samples of PVC Flooring

Phthalate

(%m/m)

Sample

NGP009

Sample

NGP010

Sample

NGP011

Sample

NGP012

Sample

NGP013

Di-isononyl

phthalate

(DINP)

8.26 4.7 14.3 15.8 7.4

Bis

ethylhexyl

phthalate

(DEHP)

≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05

Di-n-octyl

phthalate

(DnOP)

≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05

Di-butyl

phthalate

(DBP)

≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05

Di-isodecyl

phthalate

≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05 ≤ 0.05
(DIDP)

Butyl Benzyl

Phthalate

(BBP)

≤ 0.05 ≤ 0.05 4.0 1.6 5.0

Compounds

tentatively

identified:

Diheptyl

phthalate

(DHP)

- - √ √ √

Table 3. Concentration of Organotin Compounds (μg/kg) in Samples of PVC Flooring

Organotin

(μg/kg)

Sample

NGP009

Sample

NGP010

Sample

NGP011

Sample

NGP012

Sample

NGP013

Monobutyltin 5,300 1,620 48,800 330 2620

Dibutyltin 569,000 37,700 200,000 107,000 351,000

Tributyltin 17,940 128 4,390 2,730 5,100

Tetrabutyltin 12,300 138 5,770 1,440 4,350

Monooctyltin 120 980 400 <50 54

Dioctyltin 110 10,200 2,120 990 1,560

Tricyclohexyl

-tin

<50 <50 <50 <50 <50

Triphenyltin <50 <50 <50 <50 <50

Discussion

In this study, five different samples of PVC flooring purchased in the UK were analysed for

phthalates and organotins. Even though the number of samples was small, some general trends

were apparent. DINP was the predominant phthalate found and DBT was the organotin which

was found at the highest concentrations in the PVC flooring samples. Monobutyltin, TBT,

tetrabutyltin and dioctyltin were also found as chemical components in all samples, while

monooctyltin was found at somewhat lower concentrations. Tricyclohexyltin and triphenyltin

were below the limit of detection in all samples.

Regarding phthalates, DEHP has generally been recognised as the most commonly used

phthalate plasticiser for PVC, at least until recently, and Blount et al. (2000) noted that DEHP

and DINP are the phthalate esters produced in the largest quantities. In the current study, DINP,

a mixture of 30 or more isomers of dinonyl phthalate, was found in all samples in quantities

ranging from 4.7 to 15.8% by weight, whereas DEHP was below the limit of detection. The use

of DINP in PVC flooring rather than DEHP may reflect a market shift away from DEHP

towards the use of the much more poorly characterised isomeric phthalates. This shift may be a

consequence of serious concerns relating to suspected reproductive toxicity and other hazards

associated with DEHP (CSTEE 1998, Stringer et al. 2000). However, a shift to using DINP

instead of DEHP should give no room for complacency because even though DINP has been

not been studied as extensively as DEHP, it has also been shown to exhibit a range of toxic

effects in laboratory animals. Therefore there is little reason to assume that it presents less of a

potential hazard than DEHP.
BBP was found in samples NGP011, NGP012 and NGP013 at concentrations of 4.0, 1.6 and

5%. Given the high toxicity of BBP, it was not expected that this phthalate would be found as a

plasticiser in PVC flooring. This phthalate has been shown to have teratogenic, reproductive

and developmental effects in laboratory animals (see Blount et al. 2000). It has also been shown

to have endocrine-disrupting properties in offspring of rats that were exposed to the chemical

during gestation. Male offspring had significant decreases in sperm count as well as other

reproductive abnormalities at an exposure dose which approached levels to which humans are

exposed to in everyday life (Sharpe et al. 1995). Although two other studies could not repeat

these results and the reasons for these inconsistencies are not clear, the authors remain confident

of the validity of the original results (Sharpe et al. 1998). A study was undertaken recently in

the US which investigated human exposure to phthalates (Blount et al. 2000). The study

reported the presence of metabolites (breakdown products) of several phthalates in urine of

nearly 300 individuals from the general population. It concluded that phthalate exposure is both

higher and more common than previously expected, especially for BBP, DEP, and DBP. The

authors noted that this was of concern given the reproductive and developmental toxicity of

these chemicals in laboratory animals.

The presence and quantity of DINP and BBP found in PVC flooring in the present study is of

concern given the potential toxicity of these compounds and their ability to leach from PVC

potentially resulting in human exposure. It is of particular concern with respect to the health of

children. According to Oie et al. (1997) small children are subject to the highest exposure risk

from phthalate plasticisers used in surfaces in the home due to having a volume of respiration,

per kg body weight, twice as large as adults and spending much time indoors. In addition,

young children have a breathing zone close to the floor and this potentially increases their

exposure (Jaakola et al. 1999). A study in Norway recently reported a higher incidence of

bronchial obstruction among children living in homes with PVC flooring compared to children

living in homes with wood or parquet floors. The link between exposure to PVC flooring and

bronchial obstruction was suggested to possibly due to exposure to plasticisers (Jaakola et al.

1999). On this note, the use of PVC flooring in the home is of obvious concern.

The present study identified several organotin compounds as additives in PVC flooring samples.

It was not an unexpected result to find organotins in PVC flooring, particularly DBT, since it is

known that these chemicals are used as stabilisers in PVC plastic. However, the concentrations

of some organotins in the flooring samples, most notably DBT and TBT, may be considered to

be high. This is of concern given the immunotoxicity of these compounds.

PVC plastic is known to contain many different chemical additives. In the present study, a

number of organotins and phthalate plasticisers were identified in PVC flooring samples, but

these chemicals will not be the only additives present. Other hazardous chemicals such as

chlorinated paraffins will most likely also be present in some cases. Given the potential toxicity

of additives in PVC plastic to human health and to the environment, the future of this plastic is

highly questionable. Indeed, decisions have already been made by national governments of

Sweden (Swedish government Environmental Bill, adopted April 28th 1999) and Denmark

(Strategy on PVC, June 1999) which involve restrictions on PVC. At the international level,

legislation under the auspices of the OSPAR Convention is in place with regard to the phase out

of all hazardous chemicals, including organotins and certain phthalates. This agreement to

phase out all hazardous chemicals by the year 2020 was undertaken by 15 states of the North

East Atlantic Region and the European Commission. As a first step towards implementation of

the agreement, OSPAR also agreed in 1998 on a “List of Chemicals for Priority Action” (the
Priority List). The list includes organotins and the phthalates DBP and DEHP. It was agreed that

chemicals on the priority list required urgent action to address their discharges, emissions, and

losses by 2003. For the organotins, the priority action has focused on the main sources of

organotins, that is TBT in shipping and triphenyltin in agricultural use (PRAM 2000).

Conclusions

In conclusion, hazardous chemical additives, phthalates and organotins, were identified in five

samples of PVC flooring purchased in the UK. These chemicals have the potential to leach into

the environment from flooring resulting, in turn, in human exposure. This is of concern given

potential effects on health of these compounds. Measures have already been agreed at

international and national levels to phase out the use of certain phthalates and organotins on the

basis of concerns for human health and the environment. The presence of these hazardous

substances in PVC flooring highlights an important product sector which will need urgent

attention in this regard. Moreover, given that the use of hazardous additives in PVC is

seemingly unavoidable, and their leaching inevitable, the use of PVC for such applications must

be questioned.

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