On June 22, caustic soda prices in Shandong region remained generally stable with local increases. Prices: Southwest Shandong 32% ion-exchange membrane caustic soda mainstream negotiated price at 630-670 CNY/ton; Southern Shandong 32% mainstream at 680-690 CNY/ton; Western Shandong local price at 640 CNY/ton; Northern Shandong at 645-690 CNY/ton.