you could use sheet plastic, but as the ties have been there a long time, it shouldn't really be a problem - I had a decorative planter for a long time made of ties, and raised veggies in it every year - don't think it's given me any strange behaviors or terminal diseases years after the creosoted ties have rotted away

Bill

The affects that result from ingesting the by products of railroad ties, or CCA PT wood, are subtle and not always very evident, and seldom recognized as a problem from those sources without knowledgeable tests. Since what ever is going to leach from those RRties will already have gone into the soil I'd not use it for veggies but would keep growing flowers there. You may want to read the paper at the link below.

Here is a link that might be useful: Creosote exposure

Besides creosote, railroad ties have likely been treated with pentachlorophenol. My suggestion is to wrap them in something and remove them to a hazardous waste disposal site. I would take the soil out too, but you might want to just leave and continue to grow flowers in the bed.

Here is a link that might be useful: pcp

pentachlor is not used to treat RR ties - from Kimm's link " especially through direct contact with the skin during wood treatment or manufacture of coal tar creosote-treated products, or in coke or natural gas factories. Prolonged skin exposure to soot and coal tar creosote has been associated with cancer of the scrotum in chimney sweepers." - maybe I'm conditioned to any ill effects beacuse the railroad runs right behind the property i've been living on for 22 years, I know I've never worked in a creosote plant or been a chimney sweep - but then maybe we're all in dire danger from the billions of RR ties that have been treated w/ coal tar since they started using it in 1900 and spread all over the continent - or from it's use as a disinfectant, a laxative, and a cough treatment in the last century, or as a roofing material right up to today - the amount of chemical that any veg plant might pick up from very aged RR ties will be so minimal [if any] you wouldn't be able to detect the byproducts of it w/ lab tests - just don't lick the ties, and as I said, line it w/ poly if you're concerned! we all know the plastic form of petroleum is inert and can't cause problems

Bill

"pentachlor is not used to treat RR ties - from Kimm's link"

I read Kimm's link about creosote and didn't see the word pentachlorophenol mentioned at all.

The link I posted cites the Agency for Toxic Substances and Disease Registry:

"Pentachlorophenol was widely used as a pesticide and wood preservative. Since 1984, the purchase and use of pentachlorophenol has been restricted to certified applicators. It is no longer available to the general public. It is still used industrially as a wood preservative for utility poles, railroad ties, and wharf pilings."

Plastic isn't inert. I don't feel like doing the research to disprove that claim though. Also plastic doesn't biodegrade like a natural material such as a cotton fiber. It breaks down into smaller and smaller particles which remain in the environment indefinitely.

Here is a link that might be useful: atsdr

I don't mean to start a debate about plastic being so ubiquitous that we need not worry about it. For those who would like to get some idea of problems with plastic, this site has good selection of articles, studies, and so on.

Wrapping creosote & likely pcp treated railroad ties in plastic seems to me a bad idea when there are alternative bed edging materials widely available that don't carry the risks of the above.

Here is a link that might be useful: mindfully

Althea
pentachlorophenol [aside from being a most common insecticide in the past] is a preservative used instead of other things, not on top of - creosoted ties do not use it, and while various citations say it's used on ties, I haven't seen any work crews using ties other than creosoted, tho I do commonly see it's use on power poles everywhere, maybe including the ones on your street [look for the green/tan above ground level] - sorry I wasn't clearer that the 'from Kimms link' was referencing the quote following, not the statement preceeding - also my reference to plastic was sarcasm w/ reference to the ubiquitous nature of potentially hazardous materials in our society

considering the fact that Allen's ties have already been in the ground a long time, and that there's always plenty of re-useable plastic around that could be used to line the bed walls, and considering the alternative is to remove the ties and ..... send them to the landfill? ... dump them on someone elses property? ... use them somewhere else? ... not make productive use of the space? ... send them to a 'toxic waste site' [where one exists]?

I think we get a little too focused on one little 'evil' around us and lose the big picture - concerned about plastic but drive a car, made in large part of plastic and pumping toxins into the air? worry about creosote or penta, but have wood heat spewing creosote into the air, or electric heat delivered thru plastic coated wires on penta treated poles? there's a million examples in our culture, and what we need to do is find a way to limit our contribution to the problems while dealing reasonably w/ those that have crept up on us - like the ties in the yard that have done their evil deed by now - and can't have it undone by transferring them to a "toxic disposal site" where no one knows what to do w/ them anyway

Bill

Yes, I meant either/or. As you can see Bill, pcp is still allowed for treatment of rr ties, although most are treated with creosote - most, not all. I don't know if Allen knows what they had been treated with.

"Allen's ties have already been in the ground a long time,..."

I'm not sure how to interpret this. Do you mean all of the creosote or pcp has leached into the surrounding soil? That is why I would remove the soil too. I've heard creosote can remain in wood for up to 80 years.

Here in my state and I believe most if not all others, our county has a household hazardous waste collection site and to further encourage people to dispose of hazardous materials properly, sets up a neighborhood pick-up collection at least once per year. From there the materials are disposed of according to more stringent regulations than ordinary waste. Maybe BC doesn't have a similar program. My city includes plastic in the recycling progam, so I don't need to come up with creative ways of burying waste plastic in the garden.

"I think we get a little too focused on one little 'evil' around us and lose the big picture-"

Bill, what do you know about these contaminants?

"Technical grade PCP has historically contained dioxins (e.g. tetra-, hexa- and octochlorodibenzo-p-dioxin) and hexachlorobenzene as manufacturing by-products."

(http://ace.orst.edu/cgi-bin/mfs/01/pips/pentachl.htm)

"concerned about plastic but drive a car ..."

I think it is far wiser to not add hazardous products to an already contaminated environment when there is no need, than to find excuses to continue the practice. A good way to help limit our contribution to the problems is to not continue to add to the enviromental burden, especially when we know certain item/s are problematic. Removing these problematic items and disposing of them properly lessens the burden.

yes, mostly I'll agree to all that, we just differ in how to deal w/ the "problematic items" and have different views on "proper disposal" - BC has excellent recycling and hazardous waste programs, better than nearly anywhere in the US outside the major population centers, and I have some involvement in waste reduction and disposal programs here, and I make no excuses for myself or anyone else to continue contaminating the world or add to it - OTOH farmers almost everywhere use a plastic called "ag-bag" as single use storage for silage - if someone can make use of the pieces it avoids having it burned, which is mostly what happens to it

do you know how that "contaminated" soil would be dealt w/ in your area [or Allen's]? almost invariably in a 'real' decontamination site it would be bio-remediated - ie: with bacteria, composted effectively - why not do it in place instead of using more petro-resources to move it? I'm not advocating useing treated materials for raised beds, simply pointing out that we more usually go overboard w/ our revulsion for things we perceive as problematic - like all the zillion anti-whatever cleaning products that are so popular to avoid contact w/ anything in our immediate environment to the point of obsession, without thought for the cost of that behavior

myself I prefer brick, block, and steel [old truck rims are great] for raised beds since I learned long ago that no matter how wood is treated it doesn't last, particularly in a wet climate - OTOH I'll find a reasonable way to deal w/ whatever's in place, and never mind price, plastic will be much less of a problem than copper, Allen's 'expensive' alternative
it's all in the big picture, just like the RR tracks abutting the rear of my property, and the power pole right in front of me :)

Bill

allen11: Since my property is certified organic, no way can I have railroad ties (or any other Creosote-treated wood), or any pressure-treated (CCA) wood, present AT ALL. Of course I didn't need to be told that--it's just common sense, to me. Nor would I dream of eating anything grown anywhere in the vicinity of such chemical-laden wood. The whole point of my being organic is to avoid all the chemicals I possibly can--particularly those that I have direct control over, as on my own property. If I were in your postiion, I would remove the railroad ties COMPLETELY from my property, and grow any edibles far away from the location they occupied. Why even take the chance of growing food crops around such hazardous material? Surely, you wouldn't want to adversely affect the health of your family by doing so. This is a no-brainer.