Gas mixtures at all Linde Gas production and laboratory facilities are subject to professional, stringent quality checks and analyses. These audits yield accurate results and all information presented on the certificates of analysis are correct and easy to understand.
Certificates of analysis
Linde Gas operates in line with the latest version of ISO 6141, the standard that defines the information required for certificates of analysis.
All of our gas products undergo quality assessments. Our gases and gas mixtures are awarded HiQ® certificates of analysis where applicable. If a certificate of analysis is not supplied as standard, we will include it in the delivery or send it by post on request.
Our HiQ certificates of analysis contain a range of information including:
The date of the analyses
The name of the Linde Gas employee who carried out the analyses
The order number
The unique cylinder number
The contents of the cylinder and the connection
A unique certificate of analysis number
A summary containing the following details:
The composition of the gas that was ordered
The analysis result showing the actual composition of the gas
The concentration of the components in the gas cylinder will remain within the values detailed on the certificate of analysis until the specified minimum pressure has been reached.
All cylinder filling sites and laboratories at Linde Gas operate in accordance with ISO 9001/9002. Linde Gas also has other cylinder filling sites across Europe with accredited laboratories for various gases and concentrations, including carbon dioxide, carbon monoxide, propane and oxygen in nitrogen and/or air. The specialty gases plant in Munich for example is accredited according to ISO 17025, general requirement to the competence for testing and calibration laboratories. The central analytical department in Munich is even accredited according to ISO guide 34. This fulfils the general requirements for the competence of reference material producers.
Another example is the Linde Gas laboratory in Holland, which is also accredited by the Dutch Accreditation Council (RvA), an organisation recognised by other European accreditation bodies such as DAR, Swedac and Cofrac. All of these accreditations are considered to be equal to ISO 17025.
Accreditation organisations reinforce consumer trust in the quality of a product or service through independent, expert monitoring. Accreditation confirms and clarifies the value of certificates and laboratory results.
Accreditation organisations assess management systems and technical competence. They also verify that the company being accredited is unbiased and competent.
International accreditation standards ensure that products, services and organisations are assessed according to uniform standards, regardless of where the accreditation takes place. Consumers can therefore be sure that the resulting certificates and reports meet the same high criteria regardless of whether they were issued within or outside of a specific country. National accreditation organisations in Europe are part of the European co-operation for Accreditation (EA). At international level, accreditation is governed by the International Accreditation Forum (IAF), the world association of Conformity Assessment Accreditation bodies, and the International Laboratory Accreditation Cooperation (ILAC), which is the international cooperation of laboratory and inspection accreditation bodies. Both organisations work together in accreditation and certification.
National accreditation organisations can belong to these two global organisations. Multi-lateral agreement (MLA) in the EA ensures that members recognise each other's accreditations. A similar agreement also exists at international level between members of the IAF and the ILAC.
The RvA is the only Dutch organisation to have signed an MLA, which means that the (analysis) certificates and reports issued by RvA-accredited companies are recognised worldwide.
In certain applications and markets, for example the pharmaceutical and food industries, customers want and are required to know the exact origins of products.
Linde Gas provides detailed documentation on all of its traceable products, including information on each step in the value chain through to delivery to the customer.
The following is a typical process flow for liquid and cylinder gases:
Liquid gas is continually produced at a Linde Gas air separator. It is stored in one of our large storage tanks – every one of these is periodically analysed. The liquid gas is then transported to the cylinder filling station in a tanker. Here the gas cylinders are filled, analysed and approved by an authorised technician. The gas in the tanker is also analysed to detect any critical impurities.
Linde Gas also supplies traceable liquid gases directly to customers.
All of the liquid gas and cylinder gas processes described above are documented in our quality system along with the analysis results for each batch.