Within days of California’s long-anticipated single-use plastic law going into effect, environmentalists, anti-waste activists and the packaging industry reacted with anger and frustration. Anti-plastic activists say Gov. Gavin Newsom’s administration and CalRecycle inserted exemptions favoring the plastic industry into the law’s regulations that weaken it and undermine legislative intent. “These new rules create huge loopholes for plastic packaging that violate the law,” said Avinash Kar, senior director of the toxics program at the Natural Resources Defense Council. On the other side, the packaging industry has sued over similar laws in other states. “Our members have real concerns about cost, compliance, and constitutionality,” said Matt Clarke, spokesman for the National Assn. of Wholesaler-Distributors, which sued Oregon earlier this year over a similar waste law. CalRecycle, the state’s waste agency, did not respond in time for publication. The final regulations putting the law into effect were released May 1 and posted for review Tuesday. The environmental organizations say the law’s new final regulations open the door to what is known as “chemical recycling,” which produces large amounts …