Lead was, for many years, used in the production of paint (even that of a high quality), and as such was widely used throughout most households. Lead poisoning is considered as the primary environmental danger for children. It has a slightly sugary taste and so, once discovered by a child, any paintwork containing lead is naturally quite an attraction to them. The main problem associated with lead in paint is that as the paint ages and deteriorates through water or heat damage it splits and flakes resulting in dust and debris containing lead. Once ingested, lead is toxic and causes muscular paralysis, anaemia, headaches and swelling of the brain tissue resulting in epileptic seizures and mental changes.

On 29th July 1998, a law was passed which stated that any property destined for habitation and constructed before 1st January 1949 would be subjected to diagnostic testing for the presence of lead. This law has been updated on a regular basis since then to accommodate changing practices and as a result of ongoing research into the problem. It now applies to all private dwellings and from 11th August 2008 this law will apply to rental property as well. Even if a property has been renovated and repainted, the sophisticated testing equipment now used by technicians can detect lead in paint several layers below the recent covering. The technique currently used does not damage paintwork but uses an ultraviolet based apparatus to detect the lead deposits. If lead is detected, the vendor is not obliged to have any work done on the property but the buyer must be informed so that they are aware of the risks involved if they decide to strip paintwork or if existing paint has started to deteriorate. This diagnostic must be performed and a written report provided before the signing of an initial contract (compromis de vente) can take place. Failure to do this can result in an annulment of the sale. Diagnostic tests concerning lead, once performed are valid for one year, and a copy of the report must be provided in the event of a sale.

The cost of these tests will vary according to the size of the building and its age but are the responsibility of the vendor. A very rough guide price would be 150 - 200 euros for an average 4-bedroomed property.

Before selling your property, several diagnostic tests are required by law. These are dependant on the age and situation of the property including which region of France you are in. A full set of tests can cost anything up to 700 euros. It is sensible to get several quotes before proceeding with any diagnostics or ask advice from your property agent if appropriate.