Final answer:
The Combat Methamphetamine Epidemic Act of 2005 limits the amount of pseudoephedrine or ephedrine one person can purchase to 3.6 grams per day and no more than 9 grams in a 30-day period at retail stores, with mail order or mobile retail vendors having a 30-day limit of 7.5 grams.
Step-by-step explanation:
The legal restrictions on the sale of pseudoephedrine or ephedrine to an individual in a 30-day period are defined by the Combat Methamphetamine Epidemic Act of 2005. According to this act, a retailer may not sell more than 3.6 grams of these substances to a single purchaser in a single day, and no more than 9 grams to a single purchaser within a 30-day period. For mail order or mobile retail vendors, the 30-day limit for sales to a single purchaser is reduced to 7.5 grams.
The regulation is intended to prevent the misuse of ephedrine and pseudoephedrine in the illegal production of methamphetamine. To comply with the law, retailers are required to keep these substances behind the counter or in a locked cabinet and log sales in a manner that is specified by the act. Purchasers must also provide identification and sign a logbook, which retailers must maintain for at least two years.