(1) The duty levied under rule 12 shall be only for such period of time as may be necessary to prevent or remedy "market disruption".

(2) Notwithstanding anything contained in sub-rule (1) of this rule, the duty levied under rule 12 shall, unless revoked earlier, cease to have effect on the expiry of four years from the date of its imposition :

Provided that if the Central Government is of the opinion that the article on which such safeguard duty is imposed continues to be imposed into India, from People's Republic of China, in such increased quantities so as to cause or threatening to cause "market disruption" to domestic industry and the safeguard duty should continue to be imposed, it may extend the period of such imposition :

Provided further that in no case such safeguard duty shall continue to be imposed beyond a period of ten years from the date on which such duty was first imposed.