10:20 – The guys showed up this morning to start work on the driveway. They’re prepping the surface and building forms today. If the weather tomorrow is favorable, they’ll pour. Colin has been barking continuously since they arrived, shouting, “Bob! Bob! They’re stealing our driveway!”
Email from Jen overnight. She has one pack of commercial oral rehydration salts in stock, good for making up 15 liters of ORS solution. She and her husband started with the Wikipedia article and then read the other references it links to. They’re prepping for at least the six of them and possibly for two or three times that many, and they decided that 15 liters was grossly insufficient.
They didn’t want to depend on the makeshift sugar/salt solution mentioned in the article, which has much worse outcomes than the formal ORS solution, but neither did they want to spend $300 or $400 on the commercial product, so they decided to order what they’d need to make ORS solution up in bulk. As Jen said, in the larger scheme of things, it’s a very cheap prep. So she multiplied out the quantities stated in the article to determine that for each 100 liters of ORS she needs:
1350 grams (~48 ounces or 3 pounds) of anhydrous glucose
290 grams (~10.3 ounces) of trisodium citrate dihydrate
260 grams (~9.2 ounces) of sodium chloride (table salt)
150 grams (~5.3 ounces) of potassium chloride
She and her husband decided that it’d be a good idea to have at least 300 liters’ worth on hand. They obviously have table salt stored in quantity, so Jen ordered 10 pounds of anhydrous glucose, two pounds of trisodium citrate dihydrate, and a pound of potassium chloride, all food grade. She also ordered a couple bottles of zinc sulfate tablets to use with the ORS. The total cost came to well under $100. When it arrives, they’re going to repackage all the powders in foil-laminate bags with oxygen absorbers, but first Jen is going to use a scale to determine how much of each is needed by volume to make up each liter. As she says, they may not have a functioning scale when they need it, so they’ll label the bags with quantities of each component needed in teaspoons/tablespoons per liter. She also ordered a 100 gram bottle of KI, just in case. That took the total to just over $100.
11:01 – It occurs to me that I should have mentioned that Jen did not fully take my advice about buying bulk components for ORS. I actually recommended that she order them from Soapgoods, a vendor that we buy a lot of stuff from. They used to describe many of the chemicals they offered as “food grade” (FCC) or “USP”, but they discontinued doing that a couple years ago. Most of the items they sell start out as food-grade or USP, but they buy stuff by the trailer load and repackage it into smaller containers. Since their repackaging facility is not certified FCC or USP, they can’t legally describe the repackaged products as either FCC or USP. I told Jen that in my opinion it didn’t really matter, but she was more comfortable buying certified food-grade stuff. If she’d taken my advice, it would have cost noticeably less:
twelve pounds of glucose (dextrose) @ $15.18/6-lb = $30.36
two pounds of trisodium citrate dihydrate @ $3.70/lb = $7.40
one pound of potassium chloride @ $7.62 = $7.62
Or a grand total of $45.38 plus shipping, just over half of what Jen spent ordering all food grade stuff. The citrate salt is in fact the trisodium dihydrate form, which is important. (Sodium citrate, normally described just that way, may be the mono-, di-, or tri-sodium version, in various hydration states, all of which are used in foods, and the “tri” part is particularly important for ORS. The glucose (“dextrose”) sold by Soapgoods doesn’t specify hydration state. It may be anhydrous, but my strong guess is that it’s the dihydrate form.
I understand Jen’s decision. She’s not a chemist, and stuff that I’m comfortable juggling she probably isn’t. I don’t think she was particularly worried about the food-grade stuff from Soapgoods being contaminated. As I said, if she’s worried about it, she could just mix it up in boiling water, which’ll kill any biological contamination. I think it’s extremely unlikely that the product would be contaminated with other chemicals to any significant extent. But comfort level is important, and Jen was obviously more comfortable spending an extra $40 or so to get certified food-grade components.