additives

Originally posted by FMF
So that requires you to cut and paste from the net without indicating that you didn't write it. What kind of validation are you seeking?

Originally posted by normbenign
I guess he doesn't realize that scientists have opinions and express them just like everyone else.

Originally posted by FMF
So that requires you to cut and paste from the net without indicating that you didn't write it. What kind of validation are you seeking?

Originally posted by Scriabin
you are aware that none of that, which followed several opinions of mine, was offered as opinion but merely as background to describe a process.

you are also aware that I wasn't trying to establish anything with respect to my opinion thereby, only to describe the framework within which it makes sense to talk about government regulation and law with respe ...[text shortened]... on anti-intellectualism you practice

must be compensating for something really really small

Originally posted by Scriabin
must be compensating for something really really small

enough wasted time over trivialities. see http://www.epa.gov/NCEA/iris/subst/0199.htm

IRIS (Integrated Risk Information System) is a compilation of electronic reports on specific substances found in the environment and their potential to cause human health effects. The information in IRIS is intended for those without extensive training in toxicology, but with some knowledge of health sciences. the home page for IRIS is http://cfpub.epa.gov/ncea/iris/index.cfm

I want to talk about a ubiquitous industrial solvent, TCE, because it is yet to be finally assigned a regulatory maximum contaminant level or MCL. Nevertheless, much is known about TCE to give one pause.

TCE was the major contaminant that was featured in the book and movie A Civil Action -- the Woburn groundwater contamination lawsuit over leukemia deaths among children allegedly caused by pollution from W.R. Grace and Beatrice Foods in Woburn, Mass. The case never made it to a jury. In fact, it turns out the TCE did not come from either company, but that's another story. Grace certainly did violate environmental regulatory laws by burying TCE drums under its Woburn Cryovac building -- but it could not be shown to have caused any cancer deaths among neighborhood children.

TCE used to have a summary in IRIS indicating just how carcinogenic EPA thought the chemical was. But this chemical is so widespread and so much cost, liabiity by the Defense Dept in particular, caused the previous Administration to withdraw that summary "pending further review."

The same thing has been done with a number of potentially dangerous chemicals -- what we call "emerging contaminants" that have not yet had regulatory standards set for them. Chemicals like this include Ammonium Perchlorate and 1,4, dioxane. googling those will bring up some interest stuff.

try that and let's talk about anything that catches your fancy.

for example, on TCE, the Canadian government's site at http://www.ccohs.ca/oshanswers/chemicals/chem_profiles/trichloroethylene/effects_trichloro.html

says, in part:
Short-term exposure to trichloroethylene causes irritation of the nose and throat and central nervous system (CNS) depression, with symptoms such as drowsiness, dizziness, giddiness, headache, loss of coordination. High concentrations have caused numbness and facial pain, reduced eyesight, unconsciousness, irregular heartbeat and death.

Trichloroethylene is noticeable by smell at approximately 82 ppm and above. However, people can become accustomed to the odour and may not smell it until higher concentrations are reached. In one study, exposure to 110 ppm for 8 hours produced fatigue and drowsiness. Other studies have shown no significant effects following exposure to 200 or 300 ppm for less than 4 hours. At 160-250 ppm, the odour is persistent. Lightheadedness has been reported following exposure to 350-400 ppm for 3 hours. At 1000-1200 ppm, the odour is very strong and unpleasant. Lightheadedness, reduced hand-eye coordination and dizziness have been observed after several minutes. At 2000 ppm, the odour is difficult to tolerate, irritation of the nose and throat is strong, and drowsiness, dizziness and nausea occur within 5 minutes. Very high concentrations have produced death due to CNS effects, and, in rare cases, irregular heart beat. In one case, pulmonary edema (a potentially fatal accumulation of fluid in the lungs) was reported. The employee was welding a surface that had been washed in trichloroethylene. The pulmonary edema likely resulted from exposure to phosgene which is formed upon heating of trichloroethylene.

the Canadian site also says "Repeated or prolonged contact with trichloroethylene can cause dry, red and chapped skin (dermatitis). "

"Long-term occupational exposure may cause signs and symptoms of CNS depression such as headaches, dizziness, altered mood, loss of memory and inability to concentrate or sleep. These effects have also been related to long-term occupational exposure to other organic solvents and are sometimes generally referred to as "organic solvent syndrome". "

"Nerves of the face and head (cranial nerves) have been affected by long-term exposure to trichloroethylene or chemicals formed when it decomposes."

"The International Agency for Research on Cancer (IARC) has concluded that there is limited evidence for the carcinogenicity of trichloroethylene in humans. The overall IARC evaluation is that trichloroethylene is probably carcinogenic to humans (Group 2A). IARC has also concluded that there is sufficient evidence that trichloroethylene is carcinogenic in experimental animals."

so, how about this: should TCE be regulated and an MCL be set for it in the USA?

how much TCE do you want permitted in your drinking water?

how much TCE do you feel safe inhaling or putting on your skin?

what should EPA do?

Originally posted by Scriabin
the Canadian site also says...

Originally posted by normbenign
I guess he doesn't realize that scientists have opinions and express them just like everyone else.

Scriabin appreciate your posts, am still reading through them.

Originally posted by Scriabin
too simplistic a view by far. Over 4 billion pounds of toxic chemicals are released by industry into the nation's environment each year, including 72 million pounds of recognized carcinogens.

I've spent 20+ years as a government regulatory enforcement lawyer.

My experience is that disinterestedness is both possible and historically the case in many ar say, ammonium perchlorate contaminating our water supplies, or about Trichloroethylene,