What is Salbutamol? What does drug test result mean for Chris Froome and Team Sky?

Chris Froome returned an 'adverse finding' in a urine test taken on September 7, after Stage 18 of La Vuelta this year where the levels of Salbutamol exceeded the permitted levels .

The four-time Tour de France champion and his team insist he was suffering from acute asthma symptoms during the final week of the Grand Tour. The UCI has requested further information from Froome and Team Sky.

It is a medication for asthma and Chronic Obstructive Pulmonary Disease (COPD), and is also used to treat symptoms of other lung problems e.g. coughing and wheezing. The drug makes it easier to breathe by relaxing the muscles of the airways into the lungs.

It is usually dispensed via an inhaler or can sometimes be given as tablets, capsules or syrup. A prescription is required.

World Anti-Doping Authority (WADA) rules permit the use of Salbutamol – without a Therapeutic Use Exemption (TUE) – but only up to the level of 1,000 ng /ml.

Froome – a known asthma sufferer – said in his statement he was aware he would be tested after every stage as leader of the Vuelta, and so knew the increased risk of taking Salbutamol. However, on the advice of the Team Sky doctor, he decided to take a higher dose.

An investigation by The Guardian and Le Monde made the news public. They report that lawyers and scientists are working on behalf of Froome and Team Sky to challenge the result, hence why it was not confirmed.

Cycling's governing body, the UCI, also released a statement saying that Froome was notified about the test on September 20, but that it does not report potentially anti-doping rule violations unless there is a 'mandatory provisional suspension' which applies.

In this case, because Salbutamol is the substance in question, it was not required to be reported.

Read the full statement here.

Froome will hope he is able to challenge the result of the test and he and his team have offered statements insisting he suffered from acute asthma symptoms and increased his dose of Salbutamol during the final week of La Vuelta. Team Sky also claim there is evidence to show "there are unpredictable variations in how Salbutamol is metabolised and excreted" and that "no rule has been broken".

However, if he is unable to challenge the result or offer a valid explanation, he will be stripped of his Vuelta title under UCI rules. He could also face a significant suspension that would rule him out of the Giro d'Italia next year and possibly his bid to go for a record-equalling fifth yellow jersey at the Tour de France. It will also scupper his bid to hold all three Grand Tour titles at once.

In recent cases, Alessandro Petacchi was handed a 12-month ban for a having 1,320 ng/ml in his system, and, more recently, Diego Ulissi had a nine-month suspension for a recording of 1,900 ng/ml.

This is the last news Team Sky would have wanted in what has been a wretched year for them and team director, Sir Dave Brailsford, away from racing. The team, which was built on a zero-tolerance policy on drugs, has been fighting to retain its reputation after an anti-doping investigation was started into a package delivered to Sir Bradley Wiggins in 2011.

The 14-month probe was shut last month after the UK Anti-Doping Agency could not find sufficient evidence of wrongdoing. There is, however, an ongoing investigation by the digital, culture, media and sport select committee. Wiggins has always maintained his innocence.

Brailsford admitted his handling of the controversy made things "a damn sight worse than it needed to be", after failing to check his facts in what turned into a PR disaster.

Former Team Sky head coach Shane Sutton, who resigned as British Cycling technical director in April amid sexism and discrimination claims, has subsequently admitted that TUEs fit in with the mantra of Team Sky's 'marginal gains'.

So, although Team Sky have not been found guilty of any wrongdoing, the news puts them – and their star rider – under even more scrutiny ahead of what they had hoped would be a record breaking year.