Well I do wear a mask for many things, lots of solvents, the volatile and toxic ones that is, there are some that are so non-volatile they essentially lack a vapor pressure without both heat and hard vacuum. Ionic liquids, DMSO, I wouldn't bother. But I confess, it takes a fair bit of HCl gas or ammonia for me to bother sometimes, or to bother me. Of course I do so if working with anything that is a bona-fide outright virulent poison, things like white phosphorus, because I sure as shit wouldn't want to breath in white P vapour, carcinogens like benzene (causes leukaemia), or a lot of the very reactive (and often although not always, usually, the more reactive a chemical is, the more useful potential it has, but the greater danger it poses when it reacts with something you don't want it to, like your DNA, your cells or when it causes your face to spontaneously ignite, but I use plenty things like alkyl halides, that are carcinogenic, mutagenic and toxic, like say, methyl iodide, cinnamyl chloride to name a couple that come to mind, or toxic and highly corrosive and water/atmospheric moisture-reactive, low-boiling, volatile fuming liquids such as SOCl2 [thionyl chloride], concentrated acids and bases [for example use of 98% conc. sulfuric acid as a dehydrating agent in the synthesis of ethers or production of fine fluffy carbon 'foam' for structurally engineering stuff, and drying certain things that won't react with it, as sulfuric of such a strength is an extremely powerful dessicant and dehydrating agent, perhaps not the equal of phosphorus pentoxide, but it sucks water either inter or intra-molecularly like lawyers suck the blood of the living. ] or on the basic side, things like on the mild side of things, caustic soda and potassium hydroxide, somewhere in the middle, potassium tert-butoxide, for really strong bases there are the alkali metal hydrides, and things like sodamide and potassium amide and whilst I've never used it, if ever need a superbase, I need only resort to burning lithium metal and then straight away immersing it into a container filled beforehand and subjected to a stream of nitrogen to exclude O2, because alone of the alkali metals AFAIK, Li forms a nitride, that exhibits the properties of a superbase. Or Li diisopropylamide for a sterically hindered, non-nucleophilic, extremely powerful base. And there are some organic superbases that go by the name of proton sponges which again are very, very strong bases (the definition of bronsted-lowry acids and bases [as opposed to Lewis acid/bases] is that the strength of a base is defined by its ability to abstract acidic protons [these are not the protons that make up atomic nuclei, but hydrogen ions of an extranuclear nature and have no involvement with nuclear physics that I know of and certainly bog all relevant in this context] from a substrate, whilst a bronsted-lowry acid is defined by its ability to protonate [donate H+ ions) a substrate. In short, acids protonate, whilst bases deprotonate, as the primary definition of the acidity and basicity. Although of course this does not however preclude them from having additional reactivity of various kinds, such as the fact of certain acids being non-oxidizing agents, for example hydrochloric acid, phosphoric acid are non-oxidizing acids, whereas nitric (HNO3) and perchloric (HClO4) acids are powerful oxidizers, HBr, hydrobromic acid, when concentrated is specifically useful for cleaving ethers to alcohols or phenols in the case of aryl ethers, and hydriodic acid, HI, is a strong reducing agent, as are phosphorous acid and hypophosphorous acids. But it is the ability to protonate that defines a bronsted-lowry acid and to deprotonate that defines a bronsted-lowry base)
I do wear a respirator mask with ABEK-1 poly-filter cartridges, for the nastier things, and for some things I'd not work with them without a full face-enclosing mask and suit, providing positive pressure and air supply from a tank. The ABEK-1 canisters for my new mask are pretty decent IMO, in that they provide protection from organic vapours, acid gases and alkaline fumes and gases like ammonia or other volatile amines. The mask I use can also hold a pre-filter over the actual scrubber cartridges that filters out particulate shite like fine glass or asbestos fibers and other such nastiness. Although I rarely have cause to use the pre-filters because most of the hazmat materials I work with are hazardous, actually swallowing them aside, because of the vapor, are toxic gases, such as for example, chlorine, NO2, SO2, or because they contain a reactive group that is air or water/atmospheric moisture sensitive and are volatile themselves meaning the vapors hydrolyse and give off nasty fumes of their own in decomposition, such as SOCl2/thionyl chloride, which is moisture sensitive, toxic, and the vapours hydrolyze on contact with atmospheric moisture, and react violently with actual water in quantity in the liquid phase to give off sulfur dioxide and hydrogen chloride. Although rather nasty stuff, and foul smelling to boot, SOCl2 is a REALLY useful reagent, for example, capable of converting alcohols to alkyl chlorides, carboxylic acids to the corresponding acyl chloride, which are themselves excellent reagents for preparation of amides from amines, or carboxylate esters from alcohols, and SOCl2 also can, owing to its water-sensitive nature and the irreversible nature of its decomposition, well, at least under reaction conditions, its possible to make SOCl2 from SO2 and Cl2 with a catalyst tube although I've never done it myself, in a gas phase reaction passing it through a bed of heated spongy carbon, can be used for dehydration of metal chloride salts that are hydrates, such as hydrated aluminium chloride which cannot be simply roasted and the water driven off, because they decompose, to the anhydrous salts, such as for instance, by refluxing aluminium trichloride in neat SOCl2, the water of hydration reacts with the thionyl chloride to give off entirely gaseous byproducts, the sulfur dioxide and hydrogen chloride, which are easily driven off without a tedious workup, just by the heat of reflux expelling them, catching same in a scrubber tube (if one were to go put some engineering effort into designing a catalytic cycle it might even be possible to reform the SOCl2 consumed during its hydrolysis which would be fucking neat) or if not, catching the gaseous byproducts in a tank of bicarbonate or carbonate, whilst distilling off and recovering any unspent SOCl2 (its a bugger to make, requiring some nasty ass intermediate sulfur chlorides that aren't exactly a cakewalk to make and separate by distillation, moisture sensitive, acidic, highly corrosive compounds like SCl2 and disulfur dichloride, no nicer or friendlier than thionyl chloride itself, so I buy mine, although admittedly a great many hobbyists cannot purchase it, its one of the more difficult to obtain reagents, up there with red phosphorus and cyanides)
But, well, I don't let things like that get in my way:) And if I couldn't buy it I'd definitely put the effort into making it, because I enjoy the challenge, I enjoy engineering type projects as I do chemistry/bio, and love to get down and dirty so to speak (and literally after spending a day in the home machine shop I'm damn lucky to have access to, with an old but perfectly functional manually operated capstan turret lathe, mitre saws, angle and bench grinders, dremel tool, power drills, gas torches, a tungsten carbide (I think thats what it is) based wire-saw for cutting through glass and ceramics and stone, as well as diamond-cutting wheels for the angle grinder that serve if needed to cut through stone and brick. Plus the obligatory vices (believe you me, I am not short of vices
), clamps, hand-saws, hammers, chisels, screwdrivers, One thing I want though and haven't got, well two things, would be a 3-D printer, and to build a plasma torch, both for cutting and welding metals, and for use of the plasma jet for deposition of ultra-thin films of the likes of graphene, silicene and similar 1-dimensional nanomaterials for experimenting with metamaterials and of course for when something needs, to use the technical term, the fucking shit roasted out of it, such as potentially helping me prepare black phosphorus; a non-toxic, pretty thoroughly unreactive, dark, nonflammable and electrically conductive, or semiconductive allotrope (two of them actually possibly three different structures such as monoclinic and cubic black phosphorus, as well, IIRC as amorphous black P) which need generally high temperatures and pressures to prepare.
