① For silicon used in producing aluminum‑silicon alloys, an aluminum mass fraction of up to 2.0 % is permitted, with a corresponding reduction in the silicon mass fraction. In this case, the letter “A” shall be added to the silicon grade designation, e.g., Кр1A.
② For silicon intended for the chemical industry, the titanium mass fraction shall not exceed 0.2 %, with a corresponding reduction in the silicon mass fraction.
③ By agreement between the supplier and the purchaser, silicon grade Кр0 with an aluminum mass fraction of not more than 0.3 % and silicon grade Кр1 with an aluminum mass fraction of not more than 0.6 % may be produced for use in semiconductor silicon and special castings.