Bottled water: characteristics, safety and treatment
What are the different types of bottled water, and how do they differ from tap water?
In France, three different types of water can be packaged, i.e. put into bottles or refillable containers:
- natural mineral water,
- spring water,
- water made drinkable through treatment.
To comply with the regulations, natural mineral water and spring water must have an underground origin and be microbiologically safe. This water, which is characterised by its own specific microbiological composition, must be protected from any pollution. It has to meet very strict microbiological quality standards and, unlike tap water, must not undergo any disinfection treatment. The only authorised treatments are those designed to remove undesirable constituents or unstable elements such as iron and sulphur compounds. Prefectoral authorisation is needed for its exploitation and bottling, just like with the production and distribution of tap water.
Like tap water, water made drinkable through treatment may come from either groundwater or surface water resources. It must comply with the regulatory quality requirements applicable to tap water and may undergo any of the treatments authorised for tap water, including disinfection. It is not commonly marketed in France.
Spring water and water made drinkable through treatment must meet the same physico-chemical and radiological quality requirements as tap water. A person can consume them throughout a lifetime without any risk.
Natural mineral water is distinguished from other types of water by the presence of characteristic mineral elements, whose content must remain stable over time within the limits of natural fluctuation. It must meet specific physico-chemical quality requirements laid down by the regulations.
Can natural mineral water have effects on health?
As its name suggests, natural mineral water contains minerals such as magnesium, calcium and sodium. Certain types of natural mineral water, in view of their mineral concentrations, may have beneficial health effects recognised by the French National Academy of Medicine.
For example, some water containing sulphates is known to have a laxative effect while other types contribute to calcium intake. Conversely some water, due to its sodium concentration, should not be consumed in excess and may have contraindications.
Depending on their composition and the circumstances, therefore, certain types of natural mineral water may or may not be recommended. Any therapeutic use of natural mineral water falls within the medical field.
How is bottled water monitored?
The quality of this water is constantly monitored by operators and subject to health controls by the regional health agencies.
These controls include inspecting facilities, verifying measures taken by the operator to guarantee water safety and carrying out programmes of water quality analyses. The Ministerial Order of 22 October 2013 specifies the type and frequency of analyses depending on the type of exploitation, and the procedures for adapting the programmes.
These control and monitoring operations, combined with the quality of the resource and management of the bottling process's impact on water quality, ensure that natural mineral water and spring water are safe to drink (excluding specific properties linked to the mineral composition of natural mineral water).
To support these control and monitoring operations, ANSES's Nancy Laboratory for Hydrology, in its capacity as the national reference laboratory, carries out the following tasks:
- analysis of accreditation applications from laboratories involved in health controls;
- provision of scientific and technical support to the health authorities – for example, it proposes reinforced monitoring plans for bottled water;
- methodological and analytical support to health control laboratories, particularly for analysing bottled water;
- acquisition of knowledge by organising campaigns on the prevalence of emerging substances in water.
How is bottled water treated?
Use of the designations "natural mineral water" and "spring water" requires that only authorised treatment processes be used in accordance with the requirements of Directive 2009/54/EC (Articles 4 and 9). If these requirements are not met, the water may be reclassified as "water made drinkable through treatment". This reclassification has implications for the conditions under which the product is marketed, mainly in terms of labelling and pricing, irrespective of any considerations relating to its safety.
The provisions of Directive 2009/54/EC on authorised treatments for natural mineral water and spring water have been transposed into French law by the amended Ministerial Order of 14 March 2007.
The provisions on authorised treatments for water made drinkable through treatment are set out in Article R. 1321-50 of the Public Health Code.
The provisions of Directive 2009/54/EC currently authorise certain treatment processes for natural mineral water and spring water, such as filtration, to remove unstable elements such as iron and sulphur compounds, provided that this does not alter the microbiological characteristics of the water in accordance with the terms of the Directive, nor the composition of natural mineral water in its essential constituents.
However, "filtration" is a general term, and the authorised technical processes associated with it and their limitations are not specified. Moreover, apart from certain treatment processes that have been assessed by EFSA (for example, for removing iron or fluorides), the authorised filtration processes have not been harmonised at European level.
What is microfiltration?
Among the available filtration techniques, membrane microfiltration is widely used by operators and producers of natural mineral water and spring water. This technique is often preferred to sand filters, mainly because it requires less space and is easy to maintain.
The regulations governing natural mineral water and spring water authorise filtration for removing undesirable constituents or unstable elements, such as iron and sulphur compounds. However, filtration – including microfiltration – must not be used to ensure the safety of natural mineral water and spring water (the absence of pathogenic micro-organisms must be solely due to the quality of the resource). Consequently, any treatments used – including microfiltration – must not have any disinfectant properties.
Although technology has advanced considerably since 2009, there is currently no European legislation specifically governing the use of microfiltration. This is despite the fact that the structural properties of microfiltration membranes vary greatly due to the wide range of materials and processes used in their manufacture. The characteristics used to classify a microfiltration membrane therefore differ considerably depending on the type of device and the industry sector in which it will be used. Not all membranes with the same commercial description (for example, a 0.45 µm microfiltration membrane) will ultimately have the same performance, as the characteristics being measured (cut-off threshold versus average pore size, for example) or the methods used to determine them are not the same.
At the request of the Ministry of Health, ANSES analysed the microfiltration technologies used by manufacturers and the methods for determining their impact on the viable colony count of the water, taking account of advances in technology and analytical methods. Its expert appraisal therefore determined the potential impact that a microfiltration device might have on the viable colony count, depending on its characteristics. In the conclusion to its work, ANSES proposed a method for assessing the potential impact of microfiltration devices on microbiological composition (namely their retention of parameters indicating microbiological contamination of the resource or fouling of the network, and, by extrapolation, on the retention of revivable aerobic flora, a parameter used as a regulatory indicator of the viable colony count of the water) in natural mineral water and spring water. This method proposed by ANSES serves a dual purpose: to guide operators in drafting their applications for authorisation to extract and bottle the natural mineral water and spring water, and to assist the health authorities in examining these applications with respect to the criteria set out in Directive 2009/54/EC1 . The use of standardised methods (or reference methods for membrane filtration professionals) is also recommended to ensure that the characteristics, and therefore performance, of microfiltration devices can be compared with one another.
ANSES proposes that its 2026 expert appraisal provide input for a European discussion aimed at harmonising practices for the authorisation of membrane microfiltration devices.
What is ANSES’s role with regard to bottled water?
The exploitation and bottling of natural mineral water and spring water are subject to prefectoral authorisation. For this reason, in 2007, the Agency drew up guidelines for assessing the safety of natural mineral water and spring water in order to facilitate the processing of these authorisation applications by prefectoral services.
ANSES may be required to assess the health risks associated with the presence of naturally occurring elements such as manganese or organisms such as mould and yeast in bottled water. In this regard, the Agency collects data on exposure to chemical agents (TDS) and on consumption of bottled water during the national surveys it carries out (INCA and Albane).
ANSES also provides support to the services of certain ministries, particularly those responsible for health and industry, on the subject of bottled water. It takes part in scientific and technical discussions relating to the implementation of European Directive 2009/54/EC, which regulates the production and marketing of this water, such as on the assessment of microfiltration methods for natural mineral water and spring water.
The Agency’s expertise in bottled water draws on the Expert Committee on "Water", and on the skills and experience acquired by the Laboratory for Hydrology.
As bottled water is subject to EU regulations, suppliers must ensure consistent quality and consumer information across the European market. ANSES’s expert appraisals are also intended to provide input for European discussions, and it is then up to the legislator to decide whether or not to amend the provisions at EU level.
[1] Annex I to Directive 2009/54/EC, Part I, point 3, second subparagraph, and Part II, point 1.3.3