Warranted under penalty of nullity of this insurance that no manipulation of rubber involving the use of petrol, solution containing petrol or other volatile oils, with the exception of white spirit (Special Mineral Terpentine) will be carried out in the building concerned, neither in the open nor in other buildings which are under the control of the insured, provide that between the building concerned in the place or the building where manipulation as mentioned in this clause be carried out, there is an open space of at last 20m.
