The act defines critical infrastructure material as any component or part used in covered infrastructure that is made of or contains a commodity metal, the theft of which poses an imminent threat to life or the physical safety of a person, including through serious harm to the basic supply of covered infrastructure to the population or to the exercise of a core function of covered infrastructure. The act adds critical infrastructure materials to regulations in existing law on the sale and possession of commodity metals.     The act prohibits an owner, keeper, or proprietor (owner) of a junk shop, junk store, salvage yard, or junk cart or other vehicle, and every collector of or dealer in junk, salvage, or other secondhand property who buys a critical infrastructure material (buyer) from paying cash for the critical infrastructure material unless the seller is paid by means of any process in which a picture of the seller is taken or the transaction is worth less than $300.     The act prohibits a buyer from possessing critical infrastructure material without an affidavit from the seller or donator of the commodity metal. Unlawful possession of critical infrastructure materials is a class 2 misdemeanor if the amount is less than $1,000, a class 2 misdemeanor if the amount is $1,000 to $2,000, and a class 6 felony if the amount is $2,000 or more.     A buyer who unknowingly takes possession of critical infrastructure material as part of a load of otherwise noncritical infrastructure materials with an affidavit stating they can transfer the noncritical infrastructure material has a duty to notify the appropriate law enforcement agency or municipal code enforcement agency. Failure to report stolen critical infrastructure materials is a class 2 misdemeanor if the amount is less than $1,000, a class 2 misdemeanor if the amount is $1,000 to $2,000, and a class 6 felony if the amount is $2,000 or more.     An owner of a junk shop, junk store, salvage yard, or junk cart must make their book or register available to a law enforcement agency or municipal code enforcement agency upon request.     The act modifies existing criminal penalties related to the theft of commodity metals so that it is a class 6 felony for any amount that is $2,000 or more.(Note: This summary applies to this bill as enacted.)