Survey of Chemical Substances in

Consumer Products

Survey no. 25 2003

Mapping and liberation of organic

tin compounds in mattress pads,

top mattresses, and baby/junior

duvets

Jane Pors, cand. scient

René Fuhlendorff, cand. scient
2
3

1 Content

1 CONTENT 3

2 INTRODUCTION 4

3 SCOPE 5

4 MAPPING 6

4.1 MAPPING OF THE MARKET FOR TOP MATTRESSES AND BABY/JUNIOR

DUVETS 6

4.2 TOP MATTRESSES 6

4.3 BABY/JUNIOR DUVETS 6

5 ANALYTICAL METHODS 8

5.1 SAMPLE PREPARATION FOR THE ENTIRE PRODUCT 8

5.2 SAMPLE PREPARATION FOR LAYERING OF THE PRODUCT 8

5.3 ORGANIC TIN COMPOUNDS 8

5.4 MIGRATION TEST 9

6 ANALYTICAL RESULTS 10

6.1 ORGANIC TIN COMPOUNDS 10

6.2 STRATIFICATION OF PRODUCTS 12

6.3 MIGRATION TEST 16

7 SUMMARY AND CONCLUSIONS 17

7.1 CONTENT ANALYSES 17

7.2 STRATIFICATION OF THE PRODUCTS 17

7.3 MIGRATION TEST 17
4

2 Introduction

May 2002 Eurofins Danmark A/S was requested to carry out a project from

the Danish Environmental Protection Agency titled:

• Mapping and liberation of organic tin compounds in mattress pads,

top mattresses, and baby/junior duvets

The Danish Environmental Protection Agency had formulated a project

(02/05/02, http://www.mst.dk/kemi/02050112.htm) that is the basis of the

content and scope of the project.

Present project is a follow-up of a former project (performed in 2001 by

another sub-contractor than Eurofins Danmark A/S), where the Danish

Environmental Protection Agency had purchased and analysed mattress pads

and top mattresses for total tin, total antimony, permethrin, and triclosan. As

a larger amount of total tin was detected in some of the products the Danish

Environmental Protection Agency wanted this new project to investigate if a

presence of organic tin compounds could be detected in mattress pads, top

mattresses, and baby/junior duvets.

Organic tin is suspected of having long-term effects on the immune response.

Furthermore, tributyltin is known for having hormone interfering effects on

organisms in the marine environment. Other compounds are suspected of

having the same effect. Thus organic tin compounds are unwanted in

consumer products.

The producers all have had the report in hearing. From this hearing process it is

announced that product no. 3 no longer is no longer on the market

Project leaders for the Danish Environmental Protection Agency were Shima

Dobel and Anette Ejersted.

The products included in this project are anonymous in this report
5

3 Scope

A total of 17 products are included in the investigation consisting of mattress

pads, top mattresses, and baby/junior duvets.

Mattress pads are defined as a thin washable protective mattress, and top

mattresses are defined as a thicker mattress with a core of PUR

(polyurethane)-foam, latex, or the likes.

According to arrangement with the Danish Environmental Protection Agency

the project is divided into the following phases:

1. Content analyses of all products

2. Stratification of the products with detected content and products with

raised limit of detection due to interference.

3. Migration to synthetic sweat for products with detected content.
6

4 Mapping

4.1 Mapping of the market for top mattresses and baby/junior duvets

In a former project (see introduction) the largest amount of total tin was

detected in top mattresses (120-180 mg/m3 for top mattresses compared to 12

mg/m3 as the highest detected for mattress pads). Thus this project

exclusively focuses on top mattresses and baby/junior duvets made from

synthetic material as regards mapping and involvement of new products. The

original samples (mattress pads and top mattresses) are maintained as

products in the project with the exception of one single product that was

omitted.

4.2 Top mattresses

In order to obtain an overview of the top mattress market the following sales

chains and mattress producers were contacted:

Idé Møbler

Dunlopillo

IKEA

ILVA

BIVA

Jysk

VM Madrasfabrik

Getama

According to the information from the above mentioned contacts these sales

chains and mattress producers cover most of the Danish market. All top

mattresses are produced in Denmark or Sweden. The contacts gave no

information on mattresses imported from abroad besides Sweden.

Seven products have been chosen in co-operation with the Danish

Environmental Protection Agency from the contacts’ information on

production and sale. According to our information the seven products

represent the most sold mattresses, different producers, and different

materials.

The products from the former project have equally been included in the

investigation.

4.3 Baby/junior duvets

To check the market for baby and junior duvets made from synthetic material

the following have been contacted:

BabySam

Baby-Vest

Baby Dan

Jysk
7

According to information from the above mentioned chains baby and junior

duvets from synthetic material are sold in small quantities compared to

eiderdown. Duvets from synthetic material are especially sold in case of

allergy. The contacts gave no information on mattresses imported from

abroad besides Norway and Lithuania.

Two baby duvets were chosen for the project in co-operation with the Danish

Environmental Protection Agency.
8

5 Analytical methods

5.1 Sample preparation for the entire product

Six part samples are cut from each product 12 x 12 cm evenly distributed

over the entire mattress or mattress part. Three part samples are accordingly

determined for one sample and the remaining three for double determination.

Thus the single sample will represent the entire product.

Part samples consisting of layers from the entire product i.e. both core,

stuffing, and ticking. Before analysis the part samples are cut into smaller

pieces of 2-3 mm.

5.2 Sample preparation for layering of the product

A minimum of 2 part samples of 12 x 12 cm are taken from each product

evenly dispersed over the entire mattress or piece of the mattress. The

products were divided into three layers corresponding to one ticking layer

(textile), one filling layer typically made from cotton batting, and a core of

PUR foam or latex. The single layers are described under the section

“Results”.

Prior to analysis the part samples are cut into smaller pieces of 2-3 mm.

5.3 Organic tin compounds

A part sample with known weight and area is taken and extracted with acetic

acid in methanol. The extract is shaken in aqueous medium and derived at an

extractive derivation with sodium tetraethylborat and pentane. The organic

phase is added isooctane, concentrated, and analysed at combined gas

chromatography and mass spectrometry (GC/MS) at selective ion monitoring

of the substances in question. The content is calculated to relevant standards.

The analysis is performed in duplicate. The limit of detection depends on the

single component and is stated below. The unit is μg organotin cation/kg.

Component Limit of detection

Monobutyltin (MBT) 5

Dibutyltin (DBT) 5

Tributyltin (TBT) 2

Tetrabutyltin 10

Monooctyltin 10

Dioctyltin 10

Tricyclohexyltin 10

Triphenyltin 10
9

5.4 Migration test

Artificial sweat is used as simulant consisting of:

4,5 g Sodium chloride

0,3 g Potassium chloride

0,3 g Sodium sulphate

0,4 g Ammonium chloride

3,0 g Lactic acid

0,2 g Urea

1000 ml Distilled water

The sample for migration test consisted of two part samples taken two

different places on the mattress making it correspond to the content analyses.

The sample represented one mattress surface totalling 1 dm2

 equalling the

total surface of the sample 2 x 1 dm2 plus the thickness of the mattress. The

simulant is added sample the totalling covering the sample and not

compressed.

The incubation occurs at 40°C for 48 hours where after the simulant is

analysed for organic tin compounds.

The migration test is performed in duplicate.
10

6 Analytical results

6.1 Organic tin compounds

Undermentioned the results for the organic tin compounds that could be

extracted form the products. The limits of detection are stated in the table.

For some of the sample the limits of detection for all tested compounds have

been increased due to the determined low recovery of the internal standard.

The low recovery may typically be caused by problems either with derivation

or extraction from the aqueous liquid phase (e.g. emulsification caused by the

sample matrix properties). As the internal standard simulates the tested

compounds behaviour during the analytical procedure a low recovery of the

internal standard will reflect a corresponding recovery of the tested

compounds in the sample in question. This will cause a general lower

sensitivity of the method and thus an increase of the limit of detection.

There may be an increase in the limit of detection for single sample for only

one or several of the tested compounds. In such cases the reason is that other

content compounds in the sample generate (interference with) the

chromatographical analysis and prevent detection of a possible content close

to the method’s normally low limit of detection.

Table 1. The results for the analyses for extractable organic tin compounds in mattress pads, top mattresses,

and baby duvets. Two results indicate double identification. The results are stated in μg/kg.

LOD 1 2 3 4 5

Monobutyltin (MBT) 5----------

Dibutyltin (DBT) 5----------

Tributyltin (TBT) 2 - - - - - - - -33

Tetrabutyltin 10 - - - - - - - - - -

Monooctyltin 10 - - - - - - - - - -

Dioctyltin 10 - - - - - - - - - -

Tricyclohexyltin 10 - - - - - - - - - -

Triphenyltin 10 - - - - - - - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.
11

Table 1, continued. The results for the analyses for extractable organic tin compounds in mattress pads, top

mattresses, and baby duvets. Two results indicate double identification. The results are stated in μg/kg.

LOD 6 7 8 9 10

Monobutyltin (MBT) 5 - - - - - - < 20* < 20* < 10* < 10*

Dibutyltin (DBT) 5 - - - - - - < 20* < 20* < 10* < 10*

Tributyltin (TBT) 2 - - 15 19 - - < 10* < 10* < 5* < 5*

Tetrabutyltin 10 - - - - - - < 50* < 50* < 20* < 20*

Monooctyltin 10 - - - - - - < 50* < 50* < 20* < 20*

Dioctyltin 10 - - - - - - < 50* < 50* < 20* < 20*

Tricyclohexyltin 10 - - - - - - < 50* < 50* < 20* < 20*

Triphenyltin 10 - - - - - - < 50* < 50* < 20* < 20*

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

* Indicates increased limit of detection due to interference from the sample.

Table 1, continued. The results for the analyses for extractable organic tin compounds in mattress pads, top mattresses, and

baby duvets. Two results indicate double identification. The results are stated in μg/kg.

LOD 11 12 13 14 15

Monobutyltin (MBT) 5 - - < 10* < 10* - - 5 5 - -

Dibutyltin (DBT) 5 - - < 10* < 10* - - - - - -

Tributyltin (TBT) 2 - - < 5* < 5* - - - - - -

Tetrabutyltin 10 - - < 20* < 20* - - - - - -

Monooctyltin 10 - - < 20* < 20* - - - - - -

Dioctyltin 10 - - < 20* < 20* - - - - - -

Tricyclohexyltin 10 - - < 20* < 20* - - - - - -

Triphenyltin 10 - - < 20* < 20* - - - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

* Indicates increased limit of detection due to interference from the sample.
12

Table 1, continued. The results for the analyses for extractable organic tin compounds in mattress pads, top mattresses, and

baby duvets. Two results indicate double identification. The results are stated in μg/kg.

LOD 16 17

Monobutyltin (MBT) 5- - - -

Dibutyltin (DBT) 5- - - -

Tributyltin (TBT) 2- - - -

Tetrabutyltin 10 - - - -

Monooctyltin 10 - - - -

Dioctyltin 10 - - - -

Tricyclohexyltin 10 - - - -

Triphenyltin 10 - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

* Indicates increased limit of detection due to interference from the sample.

6.2 Stratification of products

The Danish Environmental Protection Agency wanted to stratify the products

where a content of one or more organic tin compounds were detected in order

to determine whether the compounds were present in all layers or exclusively

originated from one layer. Furthermore, the Danish Environmental Protection

Agency wants to include the products with increased limit of detection due to

interference. The products with detected content were 5, 7, and 14 and the

products with increased limit of detection were 9, 10, and 12.

Undermentioned the results for the organic tin compounds that could be

extracted from the single layer in the products. The limits of detection are

stated in the table.

Table 2. Results for analyses for extractable organic tin compounds in the single layer from the selected

products. Two results indicate double identification. The results are stated in μg/kg.

5

LOD Ticking Felt layer Heat layer

Monobutyltin (MBT) 5- - - - 6 6

Dibutyltin (DBT) 5- - - - - -

Tributyltin (TBT) 2- - 2 2 - -

Tetrabutyltin 10 - - - - < 50* < 50*

Monooctyltin 10 - - - - - -

Dioctyltin 10 - - - - - -

Tricyclohexyltin 10 - - - - < 50* < 50*

Triphenyltin 10 - - - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

* Indicates increased limit of detection due to interference from the sample.
13

Table 2, continued. Results for analyses for extractable organic tin compounds in the single layer from the

selected products. Two results indicate double identification. The results are stated in μg/kg.

7

LOD Ticking Felt layer Core

Monobutyltin (MBT) 5 < 10* < 10* 13 12 - -

Dibutyltin (DBT) 5 < 10* < 10* 5 5 5 7

Tributyltin (TBT) 2 < 5* < 5* 45 29 9 11

Tetrabutyltin 10 < 20* < 20* - - - -

Monooctyltin 10 < 20* < 20* - - - -

Dioctyltin 10 < 20* < 20* - - - -

Tricyclohexyltin 10 < 20* < 20* - - - -

Triphenyltin 10 < 20* < 20* - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

* Indicates increased limit of detection due to interference from the sample.

Table 2, continued. Results for analyses for extractable organic tin compounds in the single layer from the

selected products. Two results indicate double identification. The results are stated in μg/kg.

9

LOD Ticking Felt layer Core

Monobutyltin (MBT) 57 5 - - - -

Dibutyltin (DBT) 5- - - - - -

Tributyltin (TBT) 2- - - - - -

Tetrabutyltin 10 - - - - - -

Monooctyltin 10 - - - - - -

Dioctyltin 10 - - - - - -

Tricyclohexyltin 10 - - - - - -

Triphenyltin 10 - - - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.
14

Table 2, continued. Results for analyses for extractable organic tin compounds in the single layer from the

selected products. Two results indicate double identification. The results are stated in μg/kg.

10

LOD Ticking Felt layer Core

Monobutyltin (MBT) 5 - - - - < 20* < 20*

Dibutyltin (DBT) 5 - - - - < 20* < 20*

Tributyltin (TBT) 2 2 2 - - < 10* < 10*

Tetrabutyltin 10 - - - - < 40* < 40*

Monooctyltin 10 - - - - < 40* < 40*

Dioctyltin 10 - - - - < 40* < 40*

Tricyclohexyltin 10 - - - - < 40* < 40*

Triphenyltin 10 - - - - < 40* < 40*

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

* Indicates increased limit of detection due to interference from the sample.

Table 2, continued. Results for analyses for extractable organic tin compounds in the single layer from the

selected products. Two results indicate double identification. The results are stated in μg/kg.

12

LOD Ticking Felt layer Core

Monobutyltin (MBT) 5- - - - - -

Dibutyltin (DBT) 5 - - - - 14 15

Tributyltin (TBT) 2- - - - - -

Tetrabutyltin 10 - - - - < 50* < 50*

Monooctyltin 10 - - - - - -

Dioctyltin 10 - - - - - -

Tricyclohexyltin 10 - - - - < 50* < 50*

Triphenyltin 10 - - - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

* Indicates increased limit of detection due to interference from the sample.
15

Table 2, continued. Results for analyses for extractable organic tin compounds in the single layer from the

selected products. Two results indicate double identification. The results are stated in μg/kg.

14

D.G. Bolster Filtlag Core

Monobutyltin (MBT) 5 - - 12 18 - -

Dibutyltin (DBT) 5- - - - - -

Tributyltin (TBT) 2- - - - - -

Tetrabutyltin 10 - - - - - -

Monooctyltin 10 - - - - - -

Dioctyltin 10 - - - - - -

Tricyclohexyltin 10 - - - - - -

Triphenyltin 10 - - - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

In the sample with increased limits of detection (9, 10, and 12) the

interference could be concretised to one single layer (the core in sample 10) or

limited to single components in the single layer (tetrabutyltin and

tricyclohexyltin in the core of sample 12). For all three samples (9, 10, and

12) the stratification lowered the limit of detection where there was no

interference that resulted in minor amounts of organic tin compounds being

detected in the single layer.

For samples with detected amount (sample 5, 7, and 14) new components

could likewise be detected at stratification. In sample 5 MBT could be

determined in the heat layer (a woollen layer) and TBT in the felt layer. Both

values are just above the limit of detection.

For sample 7 the stratification resulted in the appearance of new components.

MBT, DBT, and TBT were all detected in the felt layer and DBT and TBT

were detected in the core. For sample 14 no “new” components were detected

at the stratification with an increase of the value for MBT and a localisation of

the felt layer.

Generally the stratification of the products resulted in a lowering of the limits

of detection thus causing new detections. Thus the stratification gave new

information compared to the original analyses.
16

6.3 Migration test

As requested by the Danish Environmental Protection Agency a migration

test was performed on the three products that contained organic tin

compounds. The simulant was artificial sweat and the test was performed at

40°C for 48 hours. The result of the test is given in table 3.

Table 3. Result for extractable organic tin compounds in the simulant. Two results indicate double

identification. The results are stated in μg/kg.

LOD 5 7 14

Monobutyltin (MBT) 0.2 - - - - - -

Dibutyltin (DBT) 0.1 - - - - - -

Tributyltin (TBT) 0.05 - - - - - -

Tetrabutyltin 0.1 - - - - - -

Monooctyltin 0.1 - - - - - -

Dioctyltin 0.1 - - - - - -

Tricyclohexyltin 0.1 - - - - - -

Triphenyltin 0.1 - - - - - -

-: Means less than the limit of detection

LOD: Indicates the limit of detection.

Provided that the limit of detection is converted is corresponds to 0.7 – 6.0

μg/kg mattress or 0.01 – 0.05 μg/dm2

.

The migration test results in no detected liberation of organic tin compounds

at simulated use of the products.
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7 Summary and conclusions

7.1 Content analyses

Tributyltin (TBT) was detected in two products and monobutyltin (MBT) in

one product at the content analyses. Furthermore, there was an increased limit

of detection for three of the products due to interference from the samples.

7.2 Stratification of the products

The Danish Environmental Protection Agency wanted determined where the

organic tin compounds occurred in the products. Therefore the three

products with determined content and the three products with increased limit

of detection were stratified and analysed.

For samples 5, 9, and 10 the results are close to the limit of detection. Due to

the stratification the interference from the samples could be concretised to one

layer or specific compounds in one single layer.

No general tendency could be determined as regards the occurrence of

organic tin in specific materials as the components could be detected in all

layers – however, not in the same product.

Generally the stratification of the products resulted in a lowering of all limits

of detection for which reason new detections occurred.

7.3 Migration test

The migration test was performed with artificial sweat as simulant and

incubated at 40°C for 48 hours. No organic tin compounds were detected in

the simulant following the migration test for which reason no exposure of the

consumer could be determined at simulated used of the products under the

given conditions.