In what concentration? The SDS is an essential tool, but you need to be able to interpret it. Almost any chemical you look at is going to have an LC50 or EC50 and some kind of data on toxicity to aquatic life. That doesn’t necessarily mean it’s so toxic it should never enter the water stream, it just means it shouldn’t be put into water sources in high concentrations.

Looking at a basic ‘geranium oil’ SDS, it’s mostly Citronellol, Geraniol, and Linalool, with miniscule amounts of a handful of others. That is probably not the best environmentally. Since Linalool and Citronellol are both antimicrobial and antifungal agents they absolutely will be somewhat harmful to aquatic life, though probably not significantly in the quantities you’d be using for shower gel.

That said, looking at Linalool, the more “toxic” component, the most sensitive subject is water fleas, with an EC50 of 20mg/L over 48hours. That means 50% of water fleas living in a medium of 20mg/L Linalool for 48 experienced harmful effects from the substance.

So, I searched a random shower gel recipe and got a basic starting point let’s say we’re going to use 7 drops of rose oil in 7 oz of liquid soap (and whatever other stuff). So that’s one drop per oz, using a rough estimate (0.05ml/drop) that gives us a concentration of 0.169% or 1.69 mL/L in your soap. A mL of liquid typically weighs roughly a gram (very roughly, but we’re just looking for a general ballpark here). Linalool makes up about 8% of the rose oil, so your overall Linalool concentration ends up roughly 135mg/L. So, the straight gel would definitely be harmful to aquatic life. But it’s not going into the water system straight, it’s mixed with the water used for bathing. Let’s say you use an entire oz of soap for a shower, and we’ve got a short shower using only 10 gallons of water. So one Oz of gel has 3.9mg of Linalool diluted into 37.8 liters of water, making a concentration around 0.1 mg/L. That’s not much, and that’s just going into more water to be diluted further.

It’s your creation, and it’s up to you to determine what level of potential harm you’re comfortable with, but moreso I hope this helps you understand better what the SDS really means and how to interpret it.

Truly the stupidest thing I’ve seen on Lemmy today, and that’s a fucking high bar to leap.

Well they did find Shmi, but by then she’d been freed and married to Cleig Lars. She did free a shitload of other slaves from Tatooine, but at that point there’s no reason to steal Shmi away from a reasonable life.

They did write a book about her trying to do this - Queen’s Shadow.