The Germans used poisonous gases as weapons at first. They used chlorine gas, but had a strong smell and was green, so it could be easily seen by the enemy. It also blew back on the Germans when they used it. They began to wear dampened material over their mouths and noses. The material worked better if they used urine instead of water. The British soldiers were given cotton pads and respirators. Death from chlorine gas was very painful, causing the victim to suffocate after suffering from burning pains in their chest. The Germans began to use a different gas, called phosgene, which they mixed with the chlorine. Phosgene was more deadly than chlorine, was colourless and smelled like mouldy hay, but it took 24 hours to take effect on the victim.