LouiseD

Is this toxic workplace making functional pots?
60% lead Bisilicate??? Your making a low fired clear glaze for hopefully non functional ware?
Get out of there. Read up on lead posioning.
Guess employer not providing sjowering facilities or total protective covering.
The occupants of the lead town are called leadheads by the ignnorant. Their brain functions affected to extent the children score WAY below the norm in all aspects of the educational testing. One example only of how lead affects the body. This is from exposure in the wide open. You are in a confined area. Dont tell me you are mixing the powders in a non protected area. Whole place washed down every night..
Laundering at home? You are pousoningbyour family 
 

Lead bisilicate is a fritted form of lead, this means it's less soluble (until fired) than raw lead. It definitely shouldn't be inhaled. Copper oxide will make a green glaze. There are National standards for the allowable amounts of leaching of lead. We don't know if the ceramics from the place you work are leaching, samples would need to be tested to ascertain the amount of leaching.
Immediate issue is for employees working there with the type of working conditions you have described. This isn't safe practice.
Second issue is the potential quality of the glazes after firing, this we don't know.
Third issue is the ethics of using a lead glaze under any circumstance. 
If there is any chance you are pregnant there is an added urgency to not expose yourself to this workplace.

Document and get a lawyer. Get samples if you can. Being asked to spray a lead glaze with no PPE is in no way shape or form safe.  This employer has NO excuse. 

Regarding lead:
"They haven't found a threshold level below which there is no harm."
"Current research hasn’t been able to determine a threshold for many of lead’s effects. That is, scientists haven’t yet found a concentration of lead below which no effect occurs."
I'm curious, is firing done in the same shop?
If so, where does the kiln vent, and what procedure/protocol for handling kiln furniture, and et cetera...

This is not my first time about hearing about lead use in England. Its still in use there for some .
Google is your friend and learning about being around it or NOT

Is the glaze recipe available?
Does it contain fritted lead?
If your employer is not educating you re all dangers when working with lead there is lack of due diligence and could lead to serious health issues.
You could be carrying lead home on your clothes and hair. It is absorbed through the skin. Can damage the brain. 
Hope the ceramic objects are not functional. Lead could leach out of glazes and poison the user.
Be careful. Very serious.
 

you might look for a totally different job, starting today.   and report the business to whatever health organization controls such places.   you do not want the next person to be affected by this ridiculously wrong ignorance.    the employers need to be stopped.

@LouiseD, as others have said this is totally unsafe and probably illegal situation to have in a workplace. Looks like you are in England, I believe the link below would either be somewhere you should report the situation too or they should be able to redirect you if not. Take some photos if you can. Even if there wasn't lead in the glaze(s) it is extremely unsafe practice to spray glaze without adequate ventilation and well fitting PPE. 
https://www.hse.gov.uk/contact/tell-us-about-a-health-and-safety-issue.htm
 

Absolutely needs reporting!!!!
Will affect everybody!! 
Please be responsible and blow the whistle.
Your family will be at risk if you launder at home or wear your clothes home.
Children in a town here are tested for blood levels of lead and are not allowed to play in the yards, mums clean houses surfaces 3-4 times a day because of wind borne lead.
Don't just get out of there  , report it.
What ceramics are being made?

If the lead is in a fritted form, apart from unsafe env. lead or no lead, would it make a difference?

Buy your own mask.treat lead exposure seriously -Read up on precautions -Google is your friend