The Act, in the first instance, applies to all non-seasonal factories using power and employing ten or more persons, and, to non-power using manufacturing units and establishments employing 20 or more persons for wages and falling within the scope of an implemented geographical area. As of now, employees of factories/ establishments, that fall within the ambit of coverage, and earning wages not exceeding Rs. 15,000/- per month are covered under the ESI Scheme.
The provisions of the ESI Act, have also been extended to the following classes of establishments under Section 1(5) of the Act.
Shops
Hotels & Restaurants, Clubs
Cinemas, including preview theatres
Newspaper Establishments
Road Motor Transport establishments
Under Section 1(5) of the ESI Act, the Appropriate Govt. is empowered to extend the Scheme to any other establishment or class of establishments, industrial, commercial, agricultural or otherwise. Thus, a State Government may extend the provisions of the Act in consultation with the ESI Corporation, and with the approval of the Central Government, after giving six months notice of its intention in the official gazette; provided that where the provisions of this Act have been brought into force in any part of State, the said provisions shall stand extended to any such establishment or class of establishments within that part if the provisions have already been extended to similar establishments or class of establishments in another part of that State
The Act, in the first instance, applies to all non-seasonal factories using power and employing ten or more persons, and, to non-power using manufacturing units and establishments employing 20 or more persons for wages and falling within the scope of an implemented geographical area. As of now, employees of factories/ establishments, that fall within the ambit of coverage, and earning wages not exceeding Rs. 15,000/- per month are covered under the ESI Scheme. 
