Testing All Three FRAKTUREX® Formulations for Hexavalent Chromium
Testing All Three FRAKTUREX® Formulations for Hexavalent Chromium
As part of our product evaluation process, all three FRAKTUREX® non-explosive demolition agent formulations were tested for the possible presence of water-soluble hexavalent chromium, Cr(VI).
The evaluation was carried out by a chemist holding a master’s degree in general chemistry using the VISOCOLOR® ECO Chromium(VI) colorimetric test kit and the special MACHEREY-NAGEL instructions for determining water-soluble chromate(VI) in cement and cement-containing products.
Three separate FRAKTUREX® formulations were tested: the Winter formulation for -5°C to 10°C, the Standard formulation for 10°C to 25°C, and the Summer formulation for 25°C to 40°C.
All three prepared samples visually matched the 0.00 mg/L comparison field. The first positive value on the test scale is 0.02 mg/L, corresponding to approximately 0.40 mg/kg Cr(VI) when the manufacturer’s conversion factor for cement is applied.
Test Summary
| Evaluation | Screening for water-soluble hexavalent chromium |
| Product tested | FRAKTUREX® non-explosive demolition agent |
| Formulations tested | Winter, Standard and Summer |
| Application temperature ranges | -5°C to 10°C, 10°C to 25°C and 25°C to 40°C |
| Substance investigated | Water-soluble hexavalent chromium – Cr(VI) |
| Test performed by | Chemist with a master’s degree in general chemistry |
| Test kit | VISOCOLOR® ECO Chromium(VI), REF 931020 |
| Manufacturer | MACHEREY-NAGEL |
| Test method | Colorimetric screening with visual comparison against a printed Cr(VI) scale |
| Sample preparation | 10 g sample mixed with 40 ml distilled water for 15 minutes and filtered |
| Filter | MN 615 ¼ folded filter |
| Test-kit range | 0.02–0.50 mg/L Cr(VI), with a 0.00 mg/L comparison field |
| Cement conversion factor | Measured mg/L value × 20 = mg/kg Cr(VI) |
| Positive control | Reference solution containing approximately 0.40 mg/L Cr(VI) |
| Result summary | All three samples visually matched the 0.00 mg/L comparison field |
| Screening interpretation | Below approximately 0.40 mg/kg water-soluble Cr(VI) |
| EU limit | 2 mg/kg water-soluble Cr(VI) for hydrated cement and cement-containing mixtures |
The Objective of the Evaluation
The purpose of this evaluation was to determine whether any of the three FRAKTUREX® formulations produced a measurable colour response indicating the presence of water-soluble Cr(VI).
Each formulation was tested separately using the same sample preparation, filtration, reagent application and visual comparison procedure.
A positive control solution containing approximately 0.40 mg/L Cr(VI) was also prepared. This control was used to verify that the reagents and colour reaction were functioning correctly during the evaluation.
Winter Formulation
Application temperature:
-5°C to 10°C
Developed for controlled concrete and rock splitting in colder working conditions.
Standard Formulation
Application temperature:
10°C to 25°C
Intended for applications under normal and moderate working temperatures.
Summer Formulation
Application temperature:
25°C to 40°C
Developed for controlled concrete and rock splitting at higher temperatures.
Who Performed the Test
The screening evaluation was carried out by a chemist with a master’s degree in general chemistry.
Relevant chemical knowledge was required for weighing and preparing the samples, performing the extraction and filtration procedure, applying the reagents and interpreting the developed colour response.
Testing Equipment and Test Principle
The prepared samples were evaluated using the VISOCOLOR® ECO Chromium(VI) colorimetric test kit, reference number 931020, manufactured by MACHEREY-NAGEL.
The test uses a visual colour-comparison method. Two measuring glasses are positioned over the comparison card. The developed colour of the reaction sample is compared with the printed Cr(VI) reference fields.
The scale includes positive reference values from 0.02 to 0.50 mg/L Cr(VI) and a 0.00 mg/L comparison field.
Special Instructions for Testing Cement-Containing Samples
The FRAKTUREX® samples were prepared according to the MACHEREY-NAGEL special instructions titled Determination of water-soluble chromate(VI) in cement.
These instructions define the extraction, filtration, dilution and calculation procedure required to convert the liquid test result in mg/L into a result expressed in mg/kg of the original dry sample.
Sample Preparation and Filtration
The solid FRAKTUREX® powder was not placed directly into the colour-comparison tester. A liquid extract was first prepared from each formulation according to the manufacturer’s cement-testing instructions.
The same sample mass, water quantity, mixing time, filtration procedure and dilution were used for all three formulations.
Filtration separated the liquid extract from suspended particles. This produced a clearer filtrate suitable for the subsequent colorimetric determination of water-soluble Cr(VI).
How the Evaluation Was Carried Out
The following procedure was repeated separately for the Winter, Standard and Summer FRAKTUREX® formulations.
Weigh 10 g of the Product Sample
A separate 10 g sample was taken from each FRAKTUREX® formulation.
Each formulation was evaluated individually to prevent cross-contamination and allow separate recording of the results.
Add 40 ml of Distilled Water
Each 10 g product sample was mixed with 40 ml of distilled water.
This extraction stage transferred the water-soluble components from the solid sample into the liquid phase.
Mix Intensively for 15 Minutes
The sample and distilled water were intensively mixed or shaken for 15 minutes.
The same extraction time was used for all three samples.
Filter the Mixture
The prepared mixture was filtered using an MN 615 ¼ folded filter.
The filtrate was collected and used for the determination of water-soluble Cr(VI).
Prepare the Two Measuring Glasses
For the VISOCOLOR® ECO procedure, 1.0 ml of filtrate and 4.0 ml of distilled water were added to each of the two measuring glasses.
The two-glass comparator arrangement helps compensate for the original colour and turbidity of the prepared sample.
Add the Cr(VI) Reagents
The required Cr-1 and Cr-2 reagents were added to the designated reaction sample according to the test-kit instructions.
The sample was mixed after each reagent addition.
Allow the Reaction to Develop
The reaction was allowed to develop for the period specified by the test-kit procedure.
After the reaction period, the measuring glasses were positioned over the printed comparison scale.
Compare and Record the Colour
The colour of each reaction sample was visually compared with the Cr(VI) reference fields on the comparison card.
All three samples visually matched the 0.00 mg/L comparison field.
Verify the Test with a Positive Control
A separate solution containing approximately 0.40 mg/L Cr(VI) was prepared as a positive control.
This control developed the expected red colour close to the 0.40 mg/L reference field.
The result confirmed that the reagents and colour-development procedure were functioning during the evaluation.
This evaluation was performed as a professional colorimetric screening test according to the manufacturer’s special instructions. It does not constitute an accredited laboratory certificate.
Results for the Three FRAKTUREX® Formulations
The results obtained for all three temperature-specific formulations were consistent.
Each prepared sample visually matched the 0.00 mg/L Cr(VI) comparison field. None of the three samples developed a colour response corresponding to the first positive value of 0.02 mg/L or any higher field.
| FRAKTUREX® formulation | Temperature range | Visual result | Converted screening result |
|---|---|---|---|
| Winter | -5°C to 10°C | Matched the 0.00 mg/L field | Below approximately 0.40 mg/kg Cr(VI) |
| Standard | 10°C to 25°C | Matched the 0.00 mg/L field | Below approximately 0.40 mg/kg Cr(VI) |
| Summer | 25°C to 40°C | Matched the 0.00 mg/L field | Below approximately 0.40 mg/kg Cr(VI) |
Standard Formulation Result – 10°C to 25°C
The first sample shown corresponds to the FRAKTUREX® Standard formulation for application temperatures between 10°C and 25°C.
The colour response visually matched the 0.00 mg/L comparison field.
Winter Formulation Result – -5°C to 10°C
The second sample corresponds to the FRAKTUREX® Winter formulation for application temperatures between -5°C and 10°C.
The colour response also visually matched the 0.00 mg/L comparison field.
Summer Formulation Result – 25°C to 40°C
The third sample corresponds to the FRAKTUREX® Summer formulation for application temperatures between 25°C and 40°C.
As with the previous samples, the developed colour visually matched the 0.00 mg/L comparison field.
Verification with a Positive Control
To verify that the reagents and testing procedure were functioning, a positive control solution containing approximately 0.40 mg/L Cr(VI) was prepared.
The control solution developed a clearly visible red colour corresponding approximately to the 0.40 mg/L reference field.
This demonstrated that the colorimetric procedure was capable of detecting Cr(VI) at the prepared control concentration.
The positive control verified that the reagents and colour-development procedure were functioning at the tested control concentration. It was not used as a replacement for a complete calibration or accredited quantitative laboratory analysis.
Converting the Test Result to mg/kg
The VISOCOLOR® ECO comparison scale expresses the measured liquid concentration in mg/L Cr(VI).
According to the MACHEREY-NAGEL cement-testing instructions, the measured result must be multiplied by a factor of 20 to express the Cr(VI) concentration in mg/kg of dry sample.
First positive test-kit value
0.02 mg/L × 20 = 0.40 mg/kg Cr(VI)
Since all three samples visually matched the 0.00 mg/L field and did not reach the first positive reference field of 0.02 mg/L, the screening result for each formulation was below approximately 0.40 mg/kg Cr(VI).
Comparison with the European Union Limit
Under REACH Annex XVII, Entry 47, cement and cement-containing mixtures must not be placed on the market or used if they contain, when hydrated, more than 2 mg/kg of water-soluble hexavalent chromium.
The limit corresponds to 0.0002% of the total dry weight of the cement.
EU maximum limit
2.00 mg/kg
FRAKTUREX® screening result
< 0.40 mg/kg
Less Than One Fifth of the EU Limit
The screening threshold of approximately 0.40 mg/kg represents only 20% of the European Union limit of 2 mg/kg.
Because all three samples remained below this screening threshold, the results indicate that the water-soluble Cr(VI) concentration was less than one fifth of the maximum EU limit.
What the Evaluation Demonstrated
- All three FRAKTUREX® formulations were tested separately.
- The test was performed by a chemist with a master’s degree in general chemistry.
- The MACHEREY-NAGEL cement-testing instructions were followed.
- Each test used 10 g of product and 40 ml of distilled water.
- The samples were intensively mixed for 15 minutes.
- The liquid extracts were filtered before colorimetric analysis.
- The VISOCOLOR® ECO Chromium(VI) test kit was used for visual comparison.
- All three samples visually matched the 0.00 mg/L comparison field.
- No sample reached the first positive value of 0.02 mg/L.
- The converted screening result was below approximately 0.40 mg/kg Cr(VI).
- A positive control produced the expected visible colour response.
- The screening result was below one fifth of the EU limit of 2 mg/kg.
Final Conclusion
This professional screening evaluation produced consistent results across all three FRAKTUREX® temperature-specific formulations.
The Winter formulation for -5°C to 10°C, the Standard formulation for 10°C to 25°C, and the Summer formulation for 25°C to 40°C all visually matched the 0.00 mg/L Cr(VI) comparison field.
None of the samples produced a colour response corresponding to the first positive test value of 0.02 mg/L. Applying the manufacturer’s conversion factor of 20 means that the screening result for each formulation was below approximately 0.40 mg/kg of water-soluble Cr(VI).
The European Union limit for hydrated cement and cement-containing mixtures is 2 mg/kg. The FRAKTUREX® screening result was therefore below a level representing one fifth of the maximum permitted EU concentration.
A separate positive control containing approximately 0.40 mg/L Cr(VI) produced the expected visible colour, confirming that the reagents and colour-development procedure were functioning during the evaluation.
Final Test Result
All three tested FRAKTUREX® formulations showed a water-soluble Cr(VI) screening result below approximately 0.40 mg/kg, less than one fifth of the European Union limit of 2 mg/kg.
Important Note
- The results apply to the tested samples and the test procedure used.
- Results were determined by visual comparison with the printed colour scale.
- A result below 0.40 mg/kg does not mean that the absolute Cr(VI) content is zero.
- The positive control verified the reaction at the prepared control concentration.
- This professional screening evaluation does not constitute an accredited laboratory certificate.
- Accredited laboratory analysis may be required where formal regulatory or conformity documentation is required.
Technical and Regulatory References
- MACHEREY-NAGEL: Determination of water-soluble chromate(VI) in cement
- MACHEREY-NAGEL: VISOCOLOR® ECO Chromium(VI), REF 931020
- European Union: REACH Regulation, Annex XVII, Entry 47
Transparent FRAKTUREX® Product Evaluation
FRAKTUREX® is a professional non-explosive demolition agent developed for controlled splitting of concrete, reinforced concrete, rock and natural stone.
Safe. Reliable. Effective.