CiToxLAB Hungary Ltd.

Veszprém - Szabadságpuszta

FINAL REPORT

Determination of the Vapour Pressure 

of Ethanedioic acid, hydrate (1:2) [CAS RN 6153-56-6] 

(hydrated form of ethanedioic acid [CAS RN 144-62-7])

Study code: 11/339-323AN

Study Director: Zsolt Sárvári, M.Sc.

20 February 2013



Study code: 11/339-323AN Final Report Page 5 of 16

STUDY TITLE: Determination of the Vapour Pressure of Ethanedioic acid, 

hydrate (1:2) [CAS RN 6153-56-6] (hydrated form of 

ethanedioic acid [CAS RN 144-62-7])

SPONSORS: Univar USA Inc.

Address: 17425 NE Union Hill Road,

Redmond, WA 98052, USA

Phone: +1 425 889 3400

Fax: +1 425 889 3760

WEGO Chemical and Mineral Corp.

Address: 239 Great Neck Road,

Great Neck, NY 11021, USA

Phone: +1 516 487 3510

Fax: +1 516 487 3794

STUDY MONITOR: John V. Massingale

Greenwich Chemical Consulting, Inc.

Address: 3300 PGA Boulevard, Suite 635

Palm Beach Gardens, FL 33410, USA

Phone: +1 561 578 8110

Fax: +1 561 578 8120

E-mail: john@grcci.com

TEST FACILITY: CiToxLAB Hungary Ltd.

(Formerly known as LAB Research Ltd. before 1st September 2011)

Address: H-8200 Veszprém, Szabadságpuszta

Hungary

Phone: +36 88-545-300

Fax: +36 88-545-301

TEST FACILITY

MANAGEMENT: Christopher Banks, DABT

Managing Director

Alyson Leyshon, M.Sc.

Senior Director of Toxicology Operations

STUDY DIRECTOR: Zsolt Sárvári M.Sc.

Phone: +36 88 545 361

E-mail: zsolt.sarvari@hu.citoxlab.com
Study code: 11/339-323AN Final Report Page 6 of 16

ASSISTANT SCIENTIST: Viktória Laky, M.Sc.

LEAD QA: Szabolcs Gáty M.Sc.

Head of Quality Assurance Unit

Vanda Gyimesi, M.Sc.

Deputy Head of QAU

RESPONSIBLE PERSONS: Ildikó Kacz - technical assistant

Andrea Egei - technical assistant

BASIS OF STUDY: - Commission Regulation (EC) No 440/2008 of 30 May 

2008 laying down test methods pursuant to Regulation 

(EC) No 1907/2006 of the European Parliament and of the 

Council on the Registration, Evaluation, Authorisation and 

Restriction of Chemicals (REACH), Method A.4, Official 

Journal of the European Union L 142 of 31 May 2008

- Organisation for Economic Co-operation and 

Development (OECD), Guidelines for Testing of 

Chemicals, Guideline No. 104, “Vapour Pressure”, 

adopted March 23, 2006
Study code: 11/339-323AN Final Report Page 7 of 16

CONTENTS

Page

1. SUMMARY 8

2. OBJECTIVE OF STUDY 8

3. MATERIALS 8

3.1. TEST ITEM 8

3.2. REFERENCE MATERIAL 9

4. TEST METHOD AND RESULTS 9

4.1. APPARATUS 9

4.2. PROCEDURE 10

4.3. RESULTS 12

5. ARCHIVES 12

6. DISTRIBUTION OF THE FINAL REPORT 12

APPENDIX 13

Copy of the GLP Certificates 14

Certificate of Analysis 16
Study code: 11/339-323AN Final Report Page 8 of 16

1. SUMMARY

This study was performed based on the U.S. Toxic Substances Control Act (TSCA) 

Section 4 Test Rule and the regulations set forth at 40 CFR 799.5087.

Vapour pressure of Ethanedioic acid was determined using MINIVAP automatic 

vapour pressure tester according to ASTM D2879-86 (isoteniscope principle). Vapour 

pressure is a measure of the substance volatility, it indicates the probability of the phase 

transitions from liquid and solid to gas phase. It is a significant factor for predicting 

atmospheric concentrations.

The measured values are outside the calibrated range. The following extrapolated result was 

obtained:

Vapour pressure of the Test Item at 20 °C: 0.34 kPa

Vapour pressure of the Test Item at 25 °C: 0.49 kPa

2. OBJECTIVE OF STUDY

The purpose of this study was to determine the vapour pressure of Ethanedioic acid, 

hydrate (1:2) [CAS RN 6153-56-6] (hydrated form of ethanedioic acid [CAS RN 144-

62-7]).

3. MATERIALS

3.1. TEST ITEM

Name: Ethanedioic acid, hydrate (1:2) [CAS RN 6153-56-6] (hydrated 

form of ethanedioic acid [CAS RN 144-62-7])

Chemical name: Oxalic acid, hydrate

CAS number: 6153-56-6

Batch/Lot number: YP2-20110704B

Molecular formula: C2H2O4×2H2O

Molecular weight: 126.1 (dihydrate form)

Appearance: White crystals

Purity: 99.71 %

Manufacture date: 04 July 2011

Expiry date: 03 July 2012

Storage conditions: Controlled room temperature (15-25o

C)

3.1.1. Identification

The test item of a suitable chemical purity was supplied by the Sponsor. All safety 

instructions required in the handling and disposal of the test item were supplied by the 

Sponsor as well.
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Identification of the test item was made by its name, batch, appearance and colour by 

Central Dispensary Unit of CiToxLAB Hungary Ltd.

3.2. REFERENCE MATERIAL

Reference Substance: Ultra-pure water

prepared by Direct-Q 3 system, Millipore

4. TEST METHOD AND RESULTS 

Start of experiment: 04 April 2012

End of experiment: 04 April 2012

4.1. APPARATUS

MINIVAP VOC, Grabner Instruments, Austria (Serial No.: 08-01-108)

DUO 2.5, Two-stage rotary vane vacuum pump, Pfeiffer Vacuum GmbH

Water purification system: MILLIPORE, DIRECT Q3, FOMNO 7334 I

Operating Principle:

The measuring principle is equivalent to ASTM D2879-86 (isoteniscope principle) but 

with only 1 ml sample volume.

The test system is composed of a vacuum-sealed measuring chamber of an overall 

volume of 5 ml. A piezoresistive pressure transducer is integrated in the vacuum 

chamber. A vacuum valve is installed in the chamber for automatic outgassing of the 

sample. Cooling and heating is performed with a Peltier element.

The apparatus was examined by measuring the vapour pressure of the reference 

substance, ultra-pure water in the 20-80 °C range in 5 °C steps. Deviation from the 

literature values (Perry's Chemical Engineer's Handbook) was less than 10 % above

20 °C . The measured values was accepted 3.09 kPa and above. Further details are

presented in Table 1.
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Table 1. Vapour pressure of water at various temperatures

Temperature

°C

Literature Data

kPa

Measured Data

kPa

Deviation

%

20 2.34 1.77 - 24.3

25 3.17 3.09 - 2.4

30 4.24 4.37 3.0

35 5.62 5.93 5.5

40 7.38 7.85 6.4

45 9.58 10.22 6.6

50 12.33 13.12 6.4

55 15.74 16.69 6.1

60 19.92 21.01 5.5

65 25.00 26.25 5.0

70 31.16 32.54 4.4

75 38.54 40.04 3.9

80 47.34 48.94 3.4

4.2. PROCEDURE

After filling approximately 1 ml of Test Item into the sample cup, the stirring magnet 

was inserted into the cup and placed into the tester. Dissolved air was removed from 

the sample by evacuation at 20°C. The vapour pressure as a function of temperature 

was registered in 20-100°C range in 5 °C steps. The measured values are presented in 

Table 2. The lowest reliable vapour pressure is 3.09 kPa.

The vapour pressure curve (log p versus 1/T) was plotted. (See Figure 1.) A line was 

fitted to the measured data (above 3.09 kPa) applying the least squares method with 

the help of Excel for Windows software. The vapour pressure was back calculated 

from the regression line for 20 and 25 °C.
Study code: 11/339-323AN Final Report Page 11 of 16

Table 2. Vapour pressure of the Test Item at various temperatures

Temperature

°C

Vapour pressure 1

kPa

Vapour pressure 2

kPa

Vapour pressure 3

kPa

Mean

kPa

20 -0.44 -0.57 -0.21 -0.41

25 -0.02 -0.39 0.41 0.00

30 0.32 -0.17 0.85 0.33

35 0.74 0.11 1.34 0.73

40 1.28 0.49 1.84 1.20

45 1.90 0.99 2.44 1.78

50 2.66 1.62 3.12 2.47

55 3.66 2.49 4.05 3.40

60 4.86 3.58 5.15 4.54

65 6.41 5.01 6.60 6.01

70 8.37 6.92 8.54 7.94

75 10.92 9.31 10.96 10.40

80 14.04 12.33 13.89 13.42

85 18.01 16.11 17.66 17.26

90 22.97 20.86 22.37 22.07

95 29.10 26.71 28.21 28.01

100 35.56 33.18 35.10 34.61

Figure 1. Vapour pressure curve of the test Item
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4.3. RESULTS

The raw data are summarized in Table 2. A log p versus 1/T diagram is presented in 

Figure 1.

Based on the simplified Clausius-Clapeyron equation a regression line was fitted on the 

measured data and the vapour pressure was extrapolated for 20 and 25 °C:

20 °C 0.34 kPa

25 °C 0.49 kPa

5. ARCHIVES

The study documents:

- study plan, amendment

- all raw data

- sample of the test item

- study report and any amendment(s)

- correspondence

are stored in the archives of CiToxLAB Hungary Ltd., Hungary 8200 Veszprém, 

Szabadságpuszta according to the Hungarian GLP and our SOP-s.

6. DISTRIBUTION OF THE FINAL REPORT

Sponsor:

- 1 × copy, bound

- 1 × copy, unbound

- 1 × pdf-file

Archives:

- 1 × original, bound
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APPENDI X
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Copy of the GLP-Certificates

The facility name until 1st September 2011 was LAB Research Ltd. From that date, the registered name has been CiToxLAB Hungary Ltd.,

this information has been transmitted to the GLP competent authority. The above GLP certificate is valid for this facility (now known as

CiToxLAB Hungary Ltd.) until the certificate expires (16 December 2012).
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Certificate of Analysis