Can laundry room chemical smells harm my dog if sealed?

Most chemicals include warnings against breathing in the fumes, even inadvertently, as they typically recommend that they are only used in well-ventilated areas. If you can smell the fumes from these chemicals in your laundry room, it's likely that Timo is also breathing them in. Different chemicals can cause different toxicities, but most/all can cause some problems, particularly if they are inhaled on a regular basis. As long as you are certain that Timo could not have ingested or touched any of the chemicals, is eating, drinking and acting normally, without any coughing or breathing concerns, you shouldn't need to seek out emergency veterinary care at this time. (Obviously, if he is doing any of those things, emergency veterinary care is needed urgently!) Otherwise, be sure to remove these chemicals from the laundry room so that they are stored in an area where no one (Timo or a person) can breathe in these fumes.