Choosing a Respirator for Bullet Casting

Choosing a Respirator for Bullet Casting

About a year ago I received some bad news from a good friend.  A long-time bullet caster who had been to the Dr. for his annual physical; he was informed his blood had tested high for dissolved lead.  It’s a well established fact that lead not only causes neurological damage associated with many heavy metals, but is also a carcinogen in humans.  Needless to say I was saddened to hear about my friend’s condition; he’d always been very careful to do his casting work outdoors and practiced good hygiene afterwards, but he’d also made what I consider to be one serious mistake– he didn’t wear a respirator.  This is something we’d argued back and forth about for years; he thought it was a waste of time, while I insisted it was worth the inconvenience.

Right after he got his results, I went to my family Dr. and had the same blood test performed.  To my relief, the results came back normal; my blood-lead level was consistent with an adult male of my age in this geographic region.  As you can probably imagine, this was one argument I was sorry to have won, but it serves as an important warning to those of us who choose to work with lead; proper safety equipment is essential to protecting your health.


Lead is a particularly insidious element; it can be absorbed easily through oral contact as well as inhalation.  Making matters worse, lead is notorious for bio-accumulating in vertebrates– Once absorbed into the human body, it binds to the bones in place of calcium, making it extraordinarily difficult to eliminate from the system.  Lead disrupts the body’s normal operation by interfering with neurological signal transmission.  This can cause things like tremors, aches & pains, nausea, memory loss and in high enough concentrations even psychosis, cancer, and ultimately death.  Suffice it to say, you don’t want lead poisoning.

Practicing good hygiene through hand-washing, not eating/drinking when working with lead, and working outdoors are all great ways to reduce your exposure, but ultimately, the fumes given off by bullet casting are just as important to address.  The best way to do this is by wearing a respirator designed to handle lead dust and fumes.

Dust & Fumes

Lead dust is created whenever you physically handle lead, while metal fumes are created when it’s melted down.  To help minimize your exposure to both these threats you need a specialized filter called an MC P100.  This particular cartridge purifies the air you breath in two different ways.  The first is chemical; MC stands for multi-contaminant.  This is a broad-spectrum charcoal filter that binds to toxic fumes and prevents you from breathing them in.  This not only helps reduce your exposure to lead fumes, but any of the other dozen or so poisonous gases generated when melting dirty, oily wheel weights down.  The second is mechanical; P100 is an international standard that guarantees a filter will block 99.97% of particulate matter, including lead dust.  These two filtration methods, working in tandem, help to dramatically reduce the hazard posed by casting lead bullets.

Finding a Respirator

Trying to find a respirator rated for both can be challenging, but here’s a simple tip for you:  the color coding used on filter cartridges is also standardized.  MC/P100 filters can be identified by a combination of an olive green sticker for the multi-contaminant filter, and a fluorescent pink outer casing for the P100 filter.  Take a quick walk down the paint supplies aisle at your local hardware store and you’ll be able to identify the proper filter just looking for these two color indicators.

Now that we’ve covered the filters, lets talk about what else you need to look for in a good respirator.  When selecting a mask it’s important to find one that fits properly.  Although cheap mesh masks are an option (for dust only), they’re just not made for this kind of application.  Instead look for a good quality mask made from silicon, vinyl, or rubber which contours well to the face, and makes a strong seal.  Likewise, you want something that’s comfortable enough you’re going to wear it.  Although many manufacturers produce high-end full-face masks, in my experience these quickly fog up and become uncomfortable, particularly on warm days.  The most expensive respirator money can buy is still worthless if you don’t wear it.

A decent respirator isn’t cheap.  At the time of this article’s publication a NIOSH certified MC/P100 unit is going to start at about $60, with a set of replacement cartridges at around $40.  Because of this it can be very tempting to try cut corners to save a buck or two.  The cheapest respirator isn’t worth jack if you can’t find replacement cartridges for it.  For that reason I strongly encourage you to stick with what’s locally available rather that buying online.  The Stanley model I currently use came from my local Canadian Tire, which will continue to stock them for many years to come.  This translates to a reliable and readily accessible source of replacement cartridges.

Likewise you may be tempted to try and buy your replacement cartridges in bulk– you don’t want to do that.  Although plain P100 filters will basically never expire, the MC charcoal components will.  Unless you’re planning to change cartridges frequently, there’s a good chance your spares will have expired before you use them.  So much for saving money.


The last thing I’m going to touch on is storage.  When you finish a casting session, it’s important to put away your respirator so it doesn’t become contaminated.  I stuff mine with clean paper towel to prevent any lead dust from the outer portion getting into the breathing area.  With that done I’ll remove both the cartridges, and place them in a sealed ziplock bag.  I do this to keep them fresh, and prevent the charcoal components from losing their potency.  I also label the bag with the date they were first used.  This helps me to keep track of how old my filters are, so I know when to replace them.


I’m happy to report that after a year of chelation therapy, my friend’s blood-lead levels have been substantially lowered.  Although they’ll never been 100% normal again, his prognosis is good, and he should live a long and happy life.  As tragic as this whole episode has been, it serves to highlight the dangers of bullet casting.  Lead doesn’t care if it’s hot out, you’re tired, or can’t afford the proper gear– If you cut corners, you will be exposed, and you will pay the price for it.

If you’re going to work with lead, you owe it to your family and yourself to do so safely, and with the proper equipment.

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