#445 Nigel Green - Tyre Testing
A sample from Nigel Green's tyre used at the World Final weekend at Buxton was tested along with five others, and returned a result that was significantly higher than all the rest for a chemical called dioctyl phthalate, which has previously been identified as common to most tyre softening products.
Nigel Green was then suspended from racing and handed down the 12 month ban that is mandatory for this offence.
On Friday October 2nd, the laboratory reported that they had retested Nigel Green's sample and had found no evidence of excessive levels of phthalate, and was at a loss to explain how the first reading had been obtained.
On Monday October 5th, a second sample from the same tyre was extracted by Board of Control officials, and sent for analysis.
On Wednesday October 7th, the laboratory reported that the fresh sample had come up again with a negative result.
On Saturday October 10th, Nigel Green was given the go ahead to resume racing.
BriSCA F2 is extremely disappointed with this situation, and will be continuing to conduct a thorough investigation into this matter, with findings to be published in due course.
A final statement from Rubber Consultants has now been forthcoming, which BriSCA F2 considers to be the concluding chapter of this matter. The relevant extract of the statement reads:
In the first test on 23 Sep 2009 a suspicious result was obtained. The level of DOP in the tyre extract was found to be significantly higher than in the other 5 samples taken on the same day.
When this result was reported RC enquired whether any additional evidence was present.
It seemed that the RC single result was the only test that had pointed to deliberate addition. In view of this RC undertook a similar test on the remaining small volume of the suspect rubber, and at the same time re-tested one of the other driver’s samples for comparison. No DOP (above the ‘baseline’ level) was detected in this remaining sample. This result was reported on 2 Oct 2009.
BriSCA decided to obtain further samples from the tyre (in the presence of the driver) and these were tested and found also to be negative.
Three subsequent tests therefore refute the original test result.
This means that there is no evidence to support the original statement in the report R12031 that said it ‘would indicate that an attempt had been made to improve tyre performance’. We therefore conclude, in view of the fact that 3 subsequent samples proved negative, that there is no reliable evidence that such an attempt was made.
The 3 negative results confirm that the appearance of DOP in the first sample is almost certainly contamination acquired post-extraction at the Rubber Consultants end. If added to the tyre before a race there would be fairly even distribution of DOP over the whole surface that would be detectable in subsequent tests.
Why was the first result obtained?
It is not possible to track the source of the elevated level of DOP. This substance appears in various rubbers and plastics, including vinyl gloves. The latter were not used in this testing, and only experienced staff were involved.
RC cannot be 100% sure that contamination was impossible and so this is a scenario that cannot be ruled out, perhaps via glassware.
In conclusion, an experienced laboratory, whether working under accreditation or not, will sometimes make mistakes or produce anomalous results. The expectation of the accrediting body is that these mistakes or anomalies will be followed up in a timely manner, and measures must be taken to arrive at a correct result and prevent a reoccurrence.