I was intending to cook a packet of sausages today but the pack was inflated. So even though they were still well within the 'Use by' date I threw them away. Was I right?
When bacteria grow on food they sometimes produce gases, which can make packaging swell. This is the most likely explanation of what happened to your pack of sausages. Because the sausages were going to be cooked, these bacteria might not have made you ill. But throwing away the food was the safest option.
Raw sausages often carry bacteria and the most likely cause of the pack's swelling is that it got warm, which would have allowed the bacteria to multiply and start releasing gases. This could happen if the sausages were out of the fridge for a while, for example, when you were bringing the shopping home. You should always try to put food in the fridge as quickly as possible, especially in warm weather, and avoid leaving food in a warm car boot.
Food might also get too warm if your fridge isn't cool enough. Using a fridge thermometer, check that the coldest part of your fridge is between 0°C and 5°C (32°F and 41°F). If your fridge has an internal freezer compartment that is iced up, this could mean that the fridge will struggle to maintain its temperature.