Hacker News Reader

Of course, the copper based antifouling that replaced TBT isn't exactly benign either. Though the new generation of siloxane based antifouling that work by being slippery and hard for organisms to attach rather than being poisonous seems promising.

https://pubs.acs.org/doi/10.1021/acs.langmuir.9b03926

When I last went in for brake pads I got to chatting with the manager and he said they’ve phased copper out of brake pads for environmental concerns.

This EPA announcement says reduce to <5% by 2021, which to me means there wasn’t a little copper but rather it was a major ingredient.

https://www.epa.gov/npdes/copper-free-brake-initiative

If the copper is bound to the hull paint well enough, maybe it’s fine? Or maybe fine in fresh water.

> If the copper is bound to the hull paint well enough, maybe it’s fine? Or maybe fine in fresh water.

If it's bound up in the paint matrix it's kind of hard for it to poison those pesky critters, no? AFAIU all biocide based anti fouling paints work by being more or less ablative, continually exposing fresh biocide to the surface.

Plastic could be a similar case. Microplastics in the air and drinking water are possibly a health hazard, yet biodegradable alternatives are more expensive or not as durable. Similar points could apply to chemicals like Bisphenol A and PFAS. A lot of substances are highly suspicious but aren't phased out because they can't be replaced easily.

Many types of plastic are also sponges for other nasty chemicals, like PCBs. So if you eat plastic from your environment you might not just be getting a dose of plastic. You might be getting a little transformer fluid, transmission fluid or dioxin in the bargain.

> interesting when you have a highly effective chemical that vastly improves performance or lifespan of something and it turns out it gives everyone cancer or seriously damages the environment

There might be a causative link. Life is parsimonious. If there is a niche, it will tend to exploit it. That means taking advantage of as many chemical pathways as possible.

Effective materials alter their environment—that is what makes them effective. But when released, uncontrolled, to disrupt the broader status quo, it follows that they are likely—somewhere—to alter a pathway critical to a life form.

The solution is containment. Effective materials should be shielded and reclaimed wherever possible. We know we can do this, because we do for chemicals toxic or very valuable to humans.

Have we tried periodically charging the hull the repel barnacles?

Or perhaps encourage a beneficial species to grow on the hill that won’t impede water flow (Eg special bacteria)

There was a Canadian scientist in the 70’s and 80’s who thought he’d figured out how to electroplate limestone out of seawater. I just a couple months ago found a little documentary from the 00’s that said someone was still giving him money to try to built artificial atolls somewhere out off of Madagascar.

At https://www.epa.gov/npdes/copper-free-brake-initiative some point between the two I came across someone who thought that what was really happening is that the electricity attracted coral polyps. So I’m wondering if charging the hull would cause very different problems?

But strictly speaking don’t sacrificial anodes already charge the hull? Doesn’t seem to slow them down much.

Yeah externalities in particular, like with CFCs or tributyltin, mess up incentives. A lot of individual benefit can be derived from pushing costs onto the general world and when the cost is individually hard to observe and/or spread out over time/space but magnified across massive numbers in total it can go on a long time. That said sometimes it's only "temporary" (which granted can be years or decades) until R&D catches up and figures out alternatives that still work but are just plain better. Like:

>Any boat owner knows the increase in speed and fuel economy from a clean hull is massive - and now you can’t get anything nearly as effective as TBT.

As far as I know there's been a lot of interesting progress on alternatives in just the last decade, even if that's not at all evenly distributed yet. I remember reading "Fouling Release Coatings: A Nontoxic Alternative to Biocidal Antifouling Coatings" [0] a decade ago as an interesting overview, and looking around seems like there has been significant progress since then. Advances in fluoropolymer brushes [1] looks pretty promising for example. Some of these may be more costly, but again the issue with the originals being "cheaper" is that they don't actually price in their true costs.

That said it would probably be more effective if there was a solid international framework and norms so that bans could be better coupled with future capital support for transition to more effective options once they come out (or best of all of course if they already exist). Including dealing with incentives around IP. If some new non/low-toxicity coatings appear that is easy for rich country users to immediately apply but folks in the Caribbean can't afford saying not merely "TBT is banned" but "we'll arrange you to get this replacement for cheap/free" might significantly reduce/eliminate ban evasion.

0: https://pubs.acs.org/doi/10.1021/cr200350v | https://sci-hub.st/10.1021/cr200350v

1: https://pubs.acs.org/doi/10.1021/acs.langmuir.6b00695

Newer review of silicone based FRC's: https://pubs.acs.org/doi/10.1021/acs.langmuir.9b03926

At this point, there are very, very few new toxic products like this that are actually necessary. TBT was only in use for 40 years, ending in about 1980. I'm sure whatever paint naval vessels used during the run-up to WWII is still good enough for most use cases today.

Similarly, I can't figure out why today's paper straws are soaked in PFAS instead of being coated in food-grade wax, as they were during the ~ 80 years before plastic straws were invented. Wax coated paper straws suck, but then, so do pfas coated paper straws, so that's not the reason.

Could it be that the wax used (as in many food-grade items) was paraffin wax, ultimately a product of the oil industry, and PFAS proved cheaper than a hydrocarbon-based solution?

I don't think that could explain it. PFAS also derive from hydrocarbons, but with more expensive chemical engineering required to get to the final product.

Micro plastic from tires is one of the biggest sources of micro plastic. And its quite toxic too. We need less cars in urban environments

Synthetic textiles also produce a lot of microplastics in the form of indoor dust.

minute amount of microplastics seems like a worthwhile tradeoff to getting stabbed by a drug addict on a bus.

Is it really about being better or about being very cost effective but poisonious options?

In a lot of these cases yes, it is truly the best chemical for the job at any price. I’m not aware of any nontoxic antifoulings that come anywhere close to TBT. If you produced anything nearly as good you could very easily sell a few gallons for _ten thousand dollars_ and I’m just talking what some small scale fisherman or guy with a boat will pay, simply because it will save them more in fuel+paint+haulouts, not even some crazy performance yachts or whatever which would pay FAR more.

You could sell it at thousands of dollars per gallon, sure, but could you sell it at a price which would support 30 years of mitigation of its effects on the marine ecosystems where the boats go? If it was popular enough to go on enough boats to kill off ten-thousand-year-old coral reefs, could you possibly charge enough to reverse that?

If you don't pay for that, you're not charging the full cost of the chemical and instead stealing those funds from the rest of society.

Both, sort of. TBT is effective because nothing grows on it. It's kinda like deet. Being bad for the environment isn't just an unintended side effect, it's a direct contributor to its effectiveness.

DEET isn't especially toxic, and while it does have negative effects on some marine life, doesn't bioaccumulate. Also, DEET doesn't rely on toxicity for its effects - it (probably) works by interfering with mosquitoes' sense of smell, and possibly also being noxious should a mosquito actually land on someone.

Which is to say, DEET is not a huge problem for the environment and any impact on the environment is not part of its effectiveness.

DEET isn't toxic, but it repels pollinators from areas where it is heavily used [1]. This isn't exclusive to DEET, every bug repellant does it to some extent, but DEET is unique because it's so damn effective.

Don't get me wrong, DEET isn't bad enough to be illegal. It washes away in the rain. It doesn't foul up groundwater, and although it does get washed into rivers and streams, it really doesn't do much once it's there.

I mention DEET as another example of a chemical that is bad for the environment because it's too good at its intended purpose - did not mean to indicate that it's as bad as that boat coating stuff.

[1]: https://www.canr.msu.edu/news/potential-impact-of-mosquito-a...

> it’s toxic to marine life

I mean... working as intended? It's marine life that makes up the growth.

The intent isn't to destroy marine life. The intent is to prevent things from sticking to and growing on the bottom of ships.

... by destroying marine life before it can stick on. The oldest antifouling were copper plates as they're an effective biocide. Lots of paints still use it today.