Starting Thursday, shoppers at the Giant Food stores in Fairfax County can look at, but not touch, soft drinks encased in plastic on the store shelves.

In the aisle near all nonreturnable soft drink containers will be a sign that reads. "Due to the Fairfax County beverage container ordinance, it is impractical at this time for us to sell nonreturnable beverage containers. If you wish to comment on this ordinance we suggest you write or call the Fairfax County Board of Supervisors."

Although Giant Food Inc., decided yesterday not to sell the non-returnable containers, many other retailers in the county said they are still trying to decide how they will comply with the ordinance.

Barry Scher, a Giant spokesman, said the sign is not a call for consumers to deluge Fairfax supervisors with uncomplimentary calls and letters. The Fairfax County Board passed an ordinance in December, 1975, which, beginning Thursday requires stores to pay at least a 5-cent refund on carbonated beverage containers and bans softing drinks in pop-top cans.

The ordinance also requires that if soft drinks in throw-away containers are sold, a label must be attached saying, "Washington Metropolitan Area, 5-cent refund." Beverages include mineral waters, like the fashionable French Perrier water, soda water and other carbonated drinks, excluding alcoholic products.

"We're simply telling the people to write to their lawmakers," Scher said."It's up to the customers to write what they want."

Last week soft drink retailers and distributors attempted to have the ordinance struck down by a court, calling it ridiclous, unfair and burdensome. But Monday, Fairfax Circuit Court Judge James Keith let the ordinance stand.

Since then the six bottlers and a local merchant have asked the Virginia Supreme Court to hear their case Thursday and Fairfax County Board Chairman John F. Harrity said it may be wise to reconsider the ordinance. Two other supervisors say the store owners should quit wasting time avoiding the law and just comply with it.

Meanwhile, several grocery chain store managers said shoppers are buying soft drinks as usual, and few seem to know about the change in their buying habits that will occur Thursday.

Safeway stores have announced no final policy, but the company is planning to mark at least some of its non-returnable soft drink containers and sell them, according to Ernie Moore, Safeway spokesman.

"We're still meeting on it now," Moore said. "There are a lot of details on it, a lot of details on marking. We will mark some products." Moore was not specific on how or what products will be marked and said that Safeway executives will continue to meet today.

A 7-Eleven store spokesman said earlier chain will clear the nonreturnables from its shelves tonight.

Charles Tabler, owner of the Foodarama Supermarket in McLean, one of the plantiffs in the case, said "Fairfax County is going to be in trouble." Soft drink buyers "are going to leave the county" to shop. Spokesmen for other stores in the county either said they were not yet sure what they will do. Others could not be reached for comment.

The ordinance's proponents say the retailers and distributors are trying to rally public support against the supervisors.

"Blackmail efforts," are "likely to stiffen resistance by the Board (of supervisors)" said James M. Scott (D-Providence), one of the ordinance's advocates.

Police Col. Kenneth R. Wilson, who is supervising the two officers who will spot check stores for violations starting Thursday, said he is not totally clear on the ordinance. For instance, there is no policy yet no handling nonreturnable bottles or pop-top soft drink cans in vending machines, Wilson said.

"It's very easy for this ordinance to be adopted," Wilson said. "But enforcing it is another thing."