After just one day of recreational marijuana sales in Washington state, and more than six months in Colorado, the questions that remain are mostly about those pot-infused food products. And, when it comes to food safety, Washington state is off to a safer start than Colorado. Only in those two states now can anyone age 21 or older purchase pot without permission from a doctor. In both states, purchases of up to an ounce of the pot plant’s buds or flowers for smoking are the most common transactions. However, pot-infused edibles have gained more notoriety in Colorado and that’s likely to continue in the Evergreen State. Washington’s voter-approved Initiative 502 allows sales of so-called “usable marijuana” and “infused product.” Unlike Colorado, the marijuana rule-makers in Washington decided that the language of the initiative does not permit the retail sale of concentrates such as hash oil. But no decision has been made on how much marijuana is required to make a food product an infused product. Washington has set limits on potency and maximum amounts for infused products. No single serving of an edible pot product can have more than 10 milligrams per serving of tetrahydrocannabinol (THC) — the chemical responsible for most of marijuana’s psychological effects — or more than 100 milligrams for a product with 10 servings. Washington limits product sizes to 16 ounces for solid edibles such as brownies and to 72 ounces for marijuana-infused liquids. Serving sizes in Washington are consistent with the rules in Colorado, at least on paper. Edible manufacturers in Colorado have not been able to achieve uniform concentrations in some products. It’s a problem that’s made it difficult for some consumers to know how much THC they are consuming. Washington state did avoid another pitfall that has hurt edibles in Colorado. The Evergreen State is subjecting all forms of marijuana — edibles, concentrates, and the smoking variety — to the same microbiological testing it imposes on all food and beverages. Colorado allowed the edible industry to get underway without requiring edible manufacturers to pass tests for such dangerous pathogens as E. coli and Salmonella. Later this fall, Colorado’s pot industry will have to play by those rules just as conventional food and beverage manufacturers do. In the meantime, millions of products have been sold without the testing used by the conventional food industry. Colorado’s voter-approved initiative made a “Marijuana Enforcement Division” the sole regulator of the state’s pot industry, and the new unit in the state Department of Revenue is primarily focused on income generation, not product safety. Pot regulation in Washington fell upon the state Liquor Control Board, which saw its 80-year retail liquor monopoly ended in 2012 by initiative only to be handed pot regulation by another initiative a year later.