I posted the following: "I am trying to make a shower gel that has a scent but is not toxic to either humans or aquatic life. And I have a hard time finding anything for the latter. Essential oils and derivatives? Nope. Synthetic ones? Nothing. I could go the unscented route, but it’s going to be hard to sell. So, considering that most of you are better informed about this topic, is there a specific ingredient that I can use for a rose fragrance that’s truly non toxic? Thanks "
On fragrange, zerowaste and sustainability. The post got deleted by mods in a manner of minutes. What the hell is going on there? I am going to stay here for much longer since that place is turning very weird. Also, can anyone here actually help me find a fragrance ingredient that won’t kill aquatic life when poured down the drain? Thank you in advance
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.