7. If, at any time after the registration of the brand of a pesticide, the Government is of opinion that the registration has been secured in violation of any of the provisions of this Ordinance or the rules or that the pesticide is ineffective against pests or hazardous to vegetation, other than weeds, or to human or animal life, the Government may, after giving to the person on whose application it had been registered an opportunity of being heard, cancel the registration.