Authorities are keeping a close watch on the prices of consumer products and food after diesel and liquefied petroleum gas (LPG) prices gained.
Boonyarit Kalayanamit, director-general of the Internal Trade Department, said Tuesday the department's officials have been assigned to closely monitor and inspect food and consumer product prices in markets.
He said it will be considered unreasonable if food vendors raise their food prices by more five baht a dish.
The department is scheduled to discuss the matter with suppliers this week to evaluate consumer product prices after diesel prices rose, affecting transport costs. It may ask suppliers to delay price hikes if their production costs increased only marginally, said Mr Boonyarit.
Diesel prices are quoted at more than 28 baht per litre, a rise from 25-26 baht per litre in December last year, while LPG prices have increased to 395 baht for a 15-kilogramme gas cylinder from 353 baht in the previous week.
The rise stems primarily from higher global crude oil prices.
He said a preliminary study by the department found higher LPG prices affect food prices by only 15-20 satang per plate.
On Monday, Commerce Minister Sontirat Sontijirawong said the ministry is studying the production cost structure, especially for products that are reliant on oil and LPG, and has assigned responsible authorities to closely monitor the product and food prices.
Somchai Pornrattanacharoen, president of the Thai Retailers and Wholesalers Association, said packed rice producers are preparing to raise prices by 20-30 baht for 5kg packs because of higher raw materials prices, while producers of daily-use products such as shampoo, soap and detergent have yet to request any price hikes, but are opting instead to reduce the size of their products.
Somkiat Makcayathorn, honorary president of the Thai Rice Packers Association, warned recently that consumers should brace for pricier packed rice, notably the hom mali variety, through the end of 2018 because of low supply and higher export demand.
Hom mali rice production is forecast to drop drastically because of heavy rains, as hom mali paddy prices have surged to 17,000-18,000 baht a tonne from 12,000 baht a year ago.