Lead Safety Per OSHA

[CNC Molds N Stuff]

As I have said, and confirmed by OSHA's summary hear:  https://www.osha.gov/lead

Lead enters the body primarily through inhalation and ingestion. Today, adults are mainly exposed to lead by breathing in lead-containing dust and fumes at work, or from hobbies that involve lead. Lead passes through the lungs into the blood where it can harm many of the body's organ systems. While inorganic lead does not readily enter the body through the skin, it can enter the body through accidental ingestion (eating, drinking, and smoking) via contaminated hands, clothing, and surfaces. Workers may develop a variety of ailments, such as neurological effects, gastrointestinal effects, anemia, and kidney disease. See the Health Effects section of this webpage for more information.

I would suggest you read the entire OSHA article at the link listed above. 

According to this document from Michigan State University lead does not become a risk for fumes until around 900 degrees Fahrenheit or about 482 degrees Celsius.  Again, I suggest you take the time to read the entire document. 

https://oem.msu.edu/images/annual_reports/lead%20hazards%20casting%20and%20reloading-sept.pdf

Know lead properties:
Lead melts at 621 °F. Fumes are released at 900°F. Lead can be breathed in and also settle on surfaces. Lead oxide (fumes mixed with air) forms a fine yellowish/brown dust. Even with good ventilation you have 100% chance of lead dust in your "Lead Area". Good hygiene and ventilation are the best way to reduce lead exposure. The main hazard activities involve hot lead - smelting, casting and handling dross (the contaminate residue that is skimmed off in the melting process)

I don't want to make light of the risks involved in handling lead, but lead is a common and useful metal used everyday in industry, small business, and hobby activities.  Many people will fear monger about lead, and there is some risk to lead handling and exposure, but education is key.  I suggest if you are considering lead casting for fishing tackle, bullet making, or reproducing parts to restore antiques that you become familiar all of the aspects of working with lead. 

Burns from spilled lead are a risk.  You will likely be working with lead well over 750F.  Much hotter than your household oven on broil setting.  Even a small spatter can be painful, and larger amounts WILL produce serious burns.

Grinding, cutting, sanding, and filing will produce lead dust.  Lead dust is a dangerous inhalation hazard.  Air filtration and a dust mask or respirator is a good reccomendation.

Handling will get a small amount of lead on your hands.  While lead is not likely to work its way through your skin, eating, drinking, smoking or picking your nose with lead on your hands does increase your exposure risk. 

Getting your lead up close to 900F and fumes will be produced.  Just don't do it.  If for some reason you are unable to get good castings under 850F its likely you have a bad batch or there is some other problem with your casting process. 

These are not all of the warnings or cautions related to working lead.  It is your responsibility to learn what you need to know in order to work safely with it, and your choice if you choose not to work with it at all or use a different metal. 

Depending on the application Tin (sticks to aluminum), Bismuth, Pewter, Zamak, and other alloys are options you may wish to look into. 

[CNC Molds N Stuff]

Oh, Good grief.  I forgot, or rather it was pointed out to me.  Molten metals are freaking hot.  You need to take care not to pour it or splash it on yourself.  Eye protection, gloves, closed towed non-melting footwear, and make sure not to drip water or other liquids into the molten pool of metal.