Have these insects in my bathroom, what are they?

[Keitai]

Had these things for a few years, what are they? How do I get rid of them?

 

[bernardgreen]

They are silverfish

What to Know About Silverfish

Find out what you need to know about silverfish, and discover the risks of a silverfish infestation and how it may affect your health.

www.webmd.com

 

[Mike13]

silver fish, they thrive on damp, but can survive a year without eating.
Boric acid by the kilo from ebay or similar will be the quickest way to get rid of them.

You do need to fix the damp they are thriving on.

 

[Notch7]

They are like a prehistoric monster if you look at them magnified

damn things eat books and will get into flour and stuff if they can

pretty hard to eradicate IME

 

[JohnD]

Repair the leak, fit a better extractor fan. Once the room is dry they will die out.

Boric acid has been taken off the domestic market due to birth defect worries.

 

[foxhole]

Boric Acid 99.9%

BORIC ACID 99.9% POWDER FORM Boric acid is a water-soluble chemical compound that consists of oxygen, boron, and hydrogen. Boric acid goes by several names, including hydrogen borate, boracic acid, and orthoboric acid. Boric acid exists in the form of colourless crystals or a white powder that...

shop.hdchemicals.co.uk

 

[JohnD]

Now try and find it in a retail shop.

Edit
I was thinking of Borax, which was traditionally a household chemical used as an insecticide and cleaner.

However, on looking up Boric Acid, I found:

"According to the CLH report for boric acid published by the Bureau for Chemical Substances Lodz, Poland, boric acid in high doses shows significant developmental toxicity and teratogenicity in rabbit, rat, and mouse fetuses as well as cardiovascular defects, skeletal variations, and mild kidney lesions.[23] As a consequence in the 30th ATP to EU directive 67/548/EEC of August 2008, the European Commission decided to amend its classification as reprotoxic category 2, and to apply the risk phrases R60 (may impair fertility) and R61 (may cause harm to the unborn child).[24][25][26][27][28]

At a 2010 European Diagnostics Manufacturing Association (EDMA) Meeting, several new additions to the Substance of Very High Concern (SVHC) candidate list in relation to the Registration, Evaluation, Authorisation and Restriction of Chemicals Regulations 2007 (REACH) were discussed. Following the registration and review completed as part of REACH, the classification of Boric Acid CAS 10043-35-3 / 11113-50-1 is listed from 1 December 2010 is H360FD (May damage fertility. May damage the unborn child.)[29][30]"

It is still sold for some industrial purposes.

 

[Mike13]

Agreed you dont want to be exposed to too much of it.
"boric acid in high doses" is the key part to note, a little bit of dust once in a while will be shrugged off easily.
You want the silverfish to get the high doses, not your family.