Group A2 and B2 refrigerants shall not be used in high probability systems where the quantity of refrigerant in any independent refrigerant circuit exceeds the amount shown in Table 18-28-1103.1. Group A3 and B3 refrigerants shall not be used except where approved. Use of these refrigerants is prohibited except in laboratories in commercial occupancies. Only unit systems containing not more than 6.6 lb (3 kg) of Group A3 or B3 refrigerant shall be used unless the laboratory is occupied by less than one person per 100 ft2 (9.3 m2) of floor area, in which case the requirements of industrial occupancies shall apply. Note that 7.4.1 permits a refrigerant charge of 6.6 lb (3 kg) or less (any refrigerant) of any system meeting the requirements of this rule.
Exception: This section does not apply to laboratories where the floor area per occupant is not less than 100 square feet (9.3 m2).
(Amend Coun. J. 11-8-12, p. 38872, § 327)