On Jun 9, 4:52 pm, Sheldon wrote:
On Jun 9, 12:50�pm, Chris wrote:



On Jun 9, 1:12 pm, "SteveB" toquerville@zionvistas wrote:

I am looking for some old railroad ties. �They have creosote treating on
them, but it is weak due to the age of the ties. �Is this a problem when
using them to form raised beds?

Steve

--
"...the man who really counts in the world is the doer, not the mere
critic-the man who actually does the work, even if roughly and imperfectly,
not the man who only talks or writes about how it ought to be done."
Theodore Roosevelt 1891

Wikipedia has this about coal tar creosote, the kind used to preserve
railroad ties:

"The International Agency for Research on Cancer (IARC) has determined
that coal tar creosote is probably carcinogenic to humans, based on
adequate animal evidence and limited human evidence. It is instructive
to note that the animal testing relied upon by IARC involved the
continuous application of creosote to the shaved skin of rodents.
After weeks of creosote application, the animals developed cancerous
skin lesions and in one test, lesions of the lung. The United States
Environmental Protection Agency has stated that coal tar creosote is a
possible human carcinogen."

Sounds like a problem to me.

Chris

Creosote occurs naturally every time wood burns; forest fires have
occured since well before there's been animal life on this planet and
still. Creosoted RR ties are essentially inert, that's how it
preserves wood... used for ground contact lumber to contain a
vegetable garden they are far safer to humans than living with the
creosote emited from a wood burning stove. Plants are very
discriminating, they don't absorb everything just because it's
there.

If the RR ties are reasonably sound I'd use them, if they are rotten
it really doesn't pay to use them to construct anything that one would
want to look decent and last a while. Real RR ties are very difficult
to work with even when new, they are typically not very consistantly
sized, and not very straight, but mostly they are darn heavy, a ten
footer can easily weigh 300 pounds... they were never meant to be used
as construction lumber... I'd not waste my time and energy
constructing a raised bed garden of any kind of rotten lumber.

I am afraid there a few incorrect things here.

First, while "creosote" does appear when burning some types of wood,
it's not the same creosote as those used to preserve RR ties. Wood
creosote was used until recently for medicinal purposes, and has never
been classed a carcinogen. The RR tie creosote is coal tar creosote,
and comes entirely from coal. It has some nasty stuff in it. When I
was a summer employee working for the US Forest Service, we used to
soak pilings in creosote- you know those logs buried in the
campgrounds to keep you from driving all over the place? We were done
up in rubber suits with welder's masks and thick rubber gloves when we
worked around the creosote drum. Maybe RR ties that have sat in the
sun and elements for 20 years or more are safe, but why take the risk?

Second, plants are really not all that discriminating. They really do
absorb almost anything that comes their way. That's why you see lush
greenery around gold and copper and lead mines- they've been planted
to absorb the highly toxic mine tailings. It's also why wetlands are
so important as water filtration sites: those plants absorb darn near
anything that gets dumped in the water. The plants in the Everglades
are toxic as hell after years of absorbing all the garbage Miami and
the sugar plantations in South Florida have dumped into the water.

Chris