The next substantial German gas attacks against the British took place from 27 to 29 April 1916, near the German-held village of Hulluch, a mile north of Loos-en-Gohelle. During the first attack on 27 April, the gas cloud and artillery bombardment were followed by raiding parties, which made temporary lodgements in the British lines. Two days later, a second gas attack was carried out at Hulluch. This time, the wind turned and blew the gas cloud back over the German lines, causing a large number of German casualties, which were increased by British troops firing at German soldiers as they fled in the open. The mixture of chlorine and phosgene was of sufficient concentration to penetrate the British PH helmet. The 16th (Irish) Division was unjustly blamed for poor gas discipline; to allay doubts as to the effectiveness of the helmet, it was put out that the gas helmets of the division were of inferior manufacture. Production of the Small Box Respirator, which had worked well during the attack, was accelerated.
