Is polyurethane dangerous for PETS?
sometime back i made a video about cutting all the mortises for the bars on a dog crate with a table saw it was an interesting process and if you want to check it out i'll put a link to that video below this one either in the expandable video description section or i'll pin it to the top of the comment section but today i want to talk about a question several people ask in regards to making wooden projects for pets or really any type of furniture that pets might come in contact with they wanted to know what wood finishes are safe for their furry family members now this is closely related to a question we dealt with in a past video and is worth dealing with again about when finishes are food safe for humans on such things as cutting boards or wooden bowls dogs don't use cutting boards but some dogs do like to chew on wood and while i'd hate to imagine what i might do if fido ate the legs on a rocking chair i'd made i could envision some poor board dog chewing on the bars of his wooden crate during the night not my dogs of course they're good girls but maybe yours so what finish is safe for dogs or kids or anything else that may chew on these bars or eat from a wooden bowl or off a cutting board pretty much anything because despite the special salad bowl finishes and other sales gimmicks that the manufacturers use to get your money and despite the woodworking magazines in the past who have bought into those gimmicks over the years finishing professionals have known all along that all common clear wood finishes are food safe once they're fully cured to be more specific the food and drug administration who regulates this sort of thing here in the u.s considers the ingredients in all commonly used clear wood finishes to be safe for contact with food intended for human consumption and one can reason that if it's safe enough for humans it must be safe enough for pets now this includes natural oils such as boiled linseed oil and tung oil even though they have metallic dryers in them as well as shellac lacquer and polyurethane varnishes and clear resins and epoxy coatings but only clear finishes because they don't really know what's necessarily going to be in the pigments that they put in the finishes and only after it's fully cured now i'm going to explain this further so please watch the whole video before you run to the comments to argue with me or i'm just going to ignore your comment i'll link below directly to title 21 of the fda's code of federal regulations this is what covers things that are fit for human consumption and specifically part 175 which discusses adhesives and coatings as indirect food additives an indirect food additive is something that is not a direct ingredient like a seasoning but which may still end up in the food through packaging or during food preparation so we're talking about things that may get in your food and be physically consumed in small amounts let's start with how the fda determines that wood finishes are safe they don't test and approve specific wood finishes like all the minwax and armor seal what they do is they look at decades of studies and data concerning the ingredients that are used to make these finishes virtually all common clear wood finishes are made up of solvents drying agents and resins different brands may blend their finishes in different ways and they don't share the proprietary information of what goes in them but they all use a combination of solvents dryers and resins solvents keep the finish in its liquid form until you apply it then they evaporate away once the finish is fully cured there's virtually no solvent left in it so that's eliminated from the equation dryers are chemical or sometimes metallic substances that make up just a tiny percentage of the finish far less than one percent in the old days it was these dryers that made people nervous about food contact with the finishes because they contained lead but no common wood finish has contained lead for at least a half century the trace amounts of the modern drying agents that remain after today's wood finishes fully cure are found on the list of substances that the fda says do not pose a risk to humans in the amounts you might consume off your cutting board or your salad bowl any more than metallic pans that you cook your food with might harm you so that leaves resins these are what make up the final film coating that protects and beautifies your wood some resins like shellac are natural substances they're literally safe to eat shellac is sprayed on fruit and vegetables candy pills coffee beans you probably eat it every day other resins like polyurethane are essentially plastic now i wouldn't sit down and eat a pound of plastic but the fda considers trace amounts of plastic such as you might get in your food from direct contact with a cutting board that's been coated in a cured wood finish to be safe for humans now you'll notice i keep saying cured wood finish and that is the key it's during that curing process that all those solvents evaporate and that's when the resins fully solidify into a form that our bodies can't break down again so a dry wood finish is not necessarily a cured wood finish if it has any smell at all it's not fully cured some natural oils may never fully cure but some of those are often edible on their own in the case of polyurethane though it takes about a month for that to fully cure so don't slap a coat on your salad bowl and call it good just because it's not sticky anymore wait for it to fully cure before you use it for food now this is where some people like to run to the comment section and pound on their keyboards because they find articles on the internet that claim all sorts of things about what can happen from what we now refer to as microplastics and common sense does tell me that the less chemicals we put in our bodies the better so i'm not going to argue that plastics can't harm humans or their pets i believe they can if consumed in sufficient quantities one study i read suggested that we all consume five grams of plastic a day it's like eating an entire credit card for breakfast each morning i don't know if that's true goodness knows i've read plenty of studies that were shown to be completely wrong by subsequent studies so citing studies that you saw online mean very little to me nor do i necessarily trust that the fda is motivated only by the best interest of you and i remember the food pyramid when we were growing up said to fill up on carbs every day so here's the way i see it a few specks of dust that may come off the finish on your cutting board when you use it is a drop in the ocean of harmful chemicals you'll consume during your lifetime so if you're worried about harmful chemicals and plastics which you probably should be cut back on the plastic water bottles a bit or the soda bottles or the ziploc bags or any number of far more dangerous things than the wood finish you're using life is about balance the 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