Are they safe?
This is an impossible question to answer simply! The real answer is that it depends on the chemical and how much of it you are exposed to. Even water is dangerous if you drink too much of it in one go. On the other hand, a very small exposure to very dangerous chemicals like cyanide can have disastrous effects on your health. What we're touching on here is the idea of risk. The risk you face from a chemical is based on the intrinsic danger of it, multiplied by your exposure to it – the amount you are exposed to, or even the length of time over which you have been exposed.
Unfortunately, we don't have an objective approach to risk as citizens. For example, when risks are taken deliberately and where we feel "in control" of the situation, we perceive the risk as being much less than it really is. Smoking and driving a car too fast are good examples of that. On the other hand, in situations where we are not in control, and where the impact of an incident may be immediate and catastrophic – like taking a flight for example – we see the risk as much higher. The reality is the reverse. Flying in an aircraft is a safe way to travel.
The news media has an important role to play here. Many of us get our information on risk from the media and we are not helped for example when one week red wine is said to be good for us and the next week we are told that it causes cancer.
On ECHA's website you can find information about the chemical substances that have been registered so far under the REACH Regulation and also those which are classified in some way and have to be labelled and specially packaged. They are referred to by their chemical names which may not be familiar to you – but nevertheless, with a little research, you can find out about the chemicals that you are exposed to in Europe.
REACH also provides you with the right to ask a retailer whether any "substances of very high concern" – the most hazardous chemicals – have been used in any product that you want to buy. The retailer has, by law, to tell you.