Respirator

A good respirator with filters specifically for Organic Vapours will make working with these chemicals easier. Note that this is more than just a particulate filter, these filters are also designed to block some of the chemical air getting through (see the notes below).

Note that some fumes will still get through the filter, and these particular respirators only help. You may also want to use work outdoors, or use a more advanced air supply if you work with chemicals regularly.

Respirator

A recommended Respirator would be the Moldex 7000 Series Reusable Half Mask Respirator link: https://www.moldex.com/product/7000-series-half-mask-respirator/ Note that we sell smaller disposable dust masks, not these.

You should purchase a filter for organic vapors such as the Moldex #7300 Organic Vapor/Acid Gas Cartridges For 7000/7800/9000 Series Respirators link: https://www.moldex.com/product/7000-7800-9000-series-respirator-organic-vapor-acid-gas-cartridge/

You don't have to go with Moldex. There are similar products from 3M. Likely any well known name brand will offer adequate protection. I would recommend buying from official distributors for a product like this. It is not worth cutting corners for a proper respirator.

Tips/Techniques

Safety Goggles Fit Better Over a Respirator than Glasses

These respirators, while very good, are not designed for use with traditional safety glasses. The seal around the cheeks and nose may cause a slightly off fit (depending on the glasses of course). This means that there is more of an opening for debris to get into your eyes. In some cases the glasses are offset slightly high, causing the bottom opening to be unacceptably large.

See the page on Safety Goggles for more details on the proper Goggles to purchase.

Goggles are Often Necessary Protection as Well

A proper gas mask will block some of the vapours, but consider that your eyes are also vulnerable to noxious gases, or especially splashing (from chemicals such as Methyl Ethyl Ketone Peroxide). You can either purchase a gas mask + goggle combination where they are all one piece or you can seperate them out in a modular fashion (which I prefer) so the goggles can be replaced if they get scratched. The benefit of using goggles is that they don't generally need any ventilation, so they can have a rubber seal.

So not only do goggles fit better around the respirator, but they may be necessary, if there are any strong vapours.

Get the Right Filters for your Application

Respirators, are a must get for working with chemicals. There are a few different filters that cover 'organic vapours'. This particular one (#7300) also covers acid gas, so it will help block some noxious acid gases (such as MEKP). For more information about different filters to purchase, see something like the Chemical Compatibility Chart which details what filters are applicable for what chemicals.

Gas Masks Do Not Block 100% of Vapor

These particular respirators (or gas masks) do not block all (organic / acid gas) vapors. You may have a false sense of security thinking that you are protected but this is not the case. For full breathing protection, you will need a seperate air supply. If you only work with casting resins a handful of times, you will be fine to skip advanced breathing protection, but on the other hand, if you are working with these on a regular basis, then you should consider doing something additional. I am referring to the actual casting of the resin. As for working with the cured parts, such as sanding or grinding, I don't have enough experience there to make a call, but I would assume it is similar.

It all depends upon how much you are using these materials. If you are working 9-5 in a resin shop, or even if it's one day on weekends over years you may see some damage if you are exposed to the resin and don't wear any protection (or even just a respirator). Note that the curing resin seems to be the most noxious (once you have added MEKP). Base resin without MEKP or catalyst added is a bit easier to deal with.

This also means, that if you were in a riot situation, and you had a mask, and there was tear gas, that you would be incorrect if you thought that the gas mask was protecting you 100% from the gas. This is not the case. The noxious gas is still damaging your lungs, but doing so below the threshold that you can tell. The natural lung pain reflex is blocked. At least with the masks that I have used. This also means that in a true war situation, that gas masks probably won't work 100%.

For a 9-5 shop, I would recommend either a positive pressure air hose setup (requires a long hose to a mask), or an oxygen concentrator and a SCBA setup (portable, can be done with relatively small oxygen tanks). Though I do not yet have personal experience with these setups as of yet.

Change Mask Filters on a Regular Basis

This goes with the previous recommendation. It's to be assumed that older filters will not work as well as newer ones. You can write the day, month, and year on each filter with a marker to keep track. Refer to the manufacturer's instructions for how often to change the filters. There is some info here: https://www.osha.gov/etools/respiratory-protection As well as in the Moldex instructions: https://web.archive.org/web/https://www.moldex.com/pdf/instructions/7000-instruction-manual.pdf