By Chris Wack 



  Lowe's Companies Inc. became the latest company to say it is adopting a nationwide standard for all customers to wear masks or face coverings when shopping in U.S. stores, effective July 20. 


  The retailer said it will offer free masks at the customer service desk of every store for customers who need them, while supplies last. 


  "As a retailer offering essential goods, we have a responsibility to our associates, customers and small businesses in communities nationwide to help provide a safe shopping experience," said Marvin R. Ellison, Lowe's president and chief executive. 


  Lowe's said it has required associates to wear masks since May, and many locations operate where state and local authorities have required customers to wear masks. 


  Write to Chris Wack at chris.wack@wsj.com