Trots*88TII-AE*

iTrader: (11)

My post was not entirely directed at you Patman, and was definitely not meant to be a personal attack in any way. It was more about my frustration with people on this forum in general regurgitating information that they do not even bother verifying themselves, such as some of the posts after yours. Either way, my outburst was uncalled for, and I apologize for that...

Now in regards to the discussion, if by searching google you mean using the American Cancer Society for its list of carcinogens, if you have a more definitive source to back your statement about Toluene being a confirmed carcinogen, I'd love to see it. But from what I see on their website and others, Toluene isn't even listed as a carcinogen in itself, it is 'toluene diisocyanate', which is apparently prepared from Toluene. I'm not saying I'm right here, I'm pointing out that I wasn't able to find any evidence that agrees with your statement. I would agree that it is not good for your health in a general sense, in the same sense that ingesting/exposure to regular gasoline is, but I wouldn't put it in a different class than any other fuel.

Also, if yourself and others in this thread are suggesting against the use of Toluene as a means to obtain higher octane fuel, then I can only assume you are suggesting using alternatives -including leaded race fuel and/or ethanol being the most common-? (which both are actually listed as carcinogens on the sources I found). Are there risks associated with Toluene that you are aware of that are not mentioned here or readily available online that would make you choose other means of increasing octane over it?

Trots*88TII-AE*

iTrader: (11)

And again, if my opinion isn't enough to put some people's mind at ease (and nor should it ever!), read this section on carcinogenicity, or for that matter the entire report located here: Toluene (CASRN 108-88-3) | IRIS | US EPA

II. Carcinogenicity Assessment for Lifetime Exposure
Substance Name — Toluene
CASRN — 108-88-3
Section II. Last Revised — 09/23/2005

This section provides information on three aspects of the carcinogenic assessment for the substance in question: the weight-of-evidence judgment of the likelihood that the substance is a human carcinogen, and quantitative estimates of risk from oral and inhalation exposure. Users are referred to Section I of this file for information on long-term toxic effects other than carcinogenicity.

The rationale and methods used to develop the carcinogenicity information in IRIS are described in the Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005). The quantitative risk estimates are derived from the application of a low-dose extrapolation procedure, and are presented in two ways to better facilitate their use. First, route-specific risk values are presented. The "oral slope factor" is an upper bound on the estimate of risk per mg/kg-day of oral exposure. Similarly, a "unit risk" is an upper bound on the estimate of risk per unit of concentration, either per µg/L drinking water (see Section II.B.1.) or per µg/m3 air breathed (see Section II.C.1.). Second, the estimated concentration of the chemical substance in drinking water or air when associated with cancer risks of 1 in 10,000, 1 in 100,000, or 1 in 1,000,000 is also provided.

II.A. Evidence for Human Carcinogenicity

__II.A.1. Weight-of-Evidence Characterization

Under the Guidelines for Carcinogen Risk Assessment (U.S. EPA, 2005), there is inadequate information to assess the carcinogenic potential of toluene because studies of humans chronically exposed to toluene are inconclusive, toluene was not carcinogenic in adequate inhalation cancer bioassays of rats and mice exposed for life (CIIT, 1980; NTP, 1990; Huff, 2003), and increased incidences of mammary cancer and leukemia were reported in a lifetime rat oral bioassay at a dose level of 500 mg/kg-day but not at 800 mg/kg-day (Maltoni et al., 1997). In the NTP (1990) and Huff (2003) studies, no neoplasms were noted in male rats, and one nasal, two kidney, and two forestomach neoplasms observed in female rats were considered not to be associated with toluene exposure. No increase in the incidence of neoplasms was observed in mice. Toluene has generally not been genotoxic in short-term testing protocols. The previous IRIS assessment classified toluene as Group D (not classifiable as to human carcinogenicity) under the Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986) based on inadequate data on the carcinogenicity of toluene in humans and inadequate evidence of carcinogenicity in animals. Toluene is not included in the 10th Report on Carcinogens (NTP, 2002). IARC has classified toluene as Group 3 (not classifiable as to its carcinogenicity in humans) with a supporting statement that there is inadequate evidence in humans and evidence suggesting a lack of carcinogenicity of toluene in experimental animals (IARC, 1999).

For more detail on Characterization of Hazard and Dose Response, exit to the toxicological review, Section 6 (PDF).

For more detail on Susceptible Populations, exit to the toxicological review, Section 4.7 (PDF).

__II.A.2. Human Carcinogenicity Data

Available studies in toluene-exposed workers have reported very limited or no evidence suggesting carcinogenic effects of toluene exposure (Anttila et al., 1998; Svensson et al., 1990; Wiebelt and Becker, 1999). A cohort mortality study in toluene-exposed workers (Wiebelt and Becker, 1999) did not report an increase in cancer-specific mortality for the entire cohort. A subcohort of highly-exposed workers demonstrated statistically significant increases in mortality from cancers of the bone and connective tissue, but lack of exposure characterization, co-exposure information, and categorization of and adjustment for other confounding factors (age, smoking, etc.) within the subcohort precludes drawing conclusions from these results as to the possible association between toluene exposure and cancer risk. Svensson et al. (1990) similarly did not report increased cancer-specific mortality among rotogravure printers. While an increase in tumors of the respiratory tract was reported, this increase was not statistically significant when only subjects with exposure periods of five years or more were examined, and no dose-response relationships were present for tumor incidence. Anttila et al. (1998) carried out a retrospective cohort analysis of 5301 workers monitored for biological markers of occupational exposure to styrene, toluene, or xylene; no significantly increased incidence rates of cancer could be associated with toluene exposure. Other studies examining the carcinogenicity of toluene in occupationally exposed humans have failed to adequately account for co-exposure to other compounds.

__II.A.3. Animal Carcinogenicity Data

NTP (1990) and Huff (2003) have conducted a 2-year inhalation carcinogenicity study in F-344 rats and B6C3F1 mice and found no evidence for carcinogenicity in either sex of either species at exposure levels up to 1200 ppm. Another inhalation carcinogenicity study in F-344 rats (CIIT, 1980; Gibson and Hardisty, 1983) likewise reported no evidence for carcinogenic effects of toluene at exposure levels up to 300 ppm. A lifetime carcinogenicity study in Sprague-Dawley rats by the oral route (Maltoni et al., 1997) was suggestive of potential carcinogenic effects of toluene, but the dose-response relationships were not well defined (i.e., the 500 mg/kg animals had considerably more tumors than those in the 800 mg/kg group) and study details were inadequately reported.

__II.A.4. Supporting Data for Carcinogenicity

Available studies examining the genotoxic effects of toluene have generally reported negative results. Toluene was found to be nonmutagenic in reverse mutation assays with S. typhimurium (Mortelmans and Riccio, 1980; Nestmann et al., 1980; Bos et al., 1981; Litton Bionetics, Inc., 1981; Snow et al., 1981; Connor et al., 1985; Nakamura et al., 1987; NTP, 1990) and E. coli (Fluck et al., 1976; Mortelmans and Riccio, 1980) with and without metabolic activation. Toluene did not induce mitotic gene conversion (Litton Bionetics, Inc., 1981; Mortelmans and Riccio, 1980) or mitotic crossing over (Mortelmans and Riccio, 1980) in S. cerevisiae. Although Litton Bionetics, Inc. (1981) reported that toluene did not cause increased chromosomal aberrations in bone marrow cells, several Russian studies (Lyapkalo, 1973; Dobrokhotov and Enikeev, 1977) report toluene as effective in causing chromosomal damage in bone marrow cells of rats. There was no evidence of chromosomal aberrations in blood lymphocytes of workers exposed to toluene only (Forni et al., 1971; Maki-Paakkanen et al., 1980), although a slight increase was noted in workers co-exposed to toluene and benzene (Forni et al., 1971; Funes-Craviota et al., 1977). This finding is supported by studies of cultured human lymphocytes exposed to toluene in vitro; no elevation of chromosomal aberrations or sister chromatid exchanges was observed (Gerner-Smidt and Friedrich, 1978).

Better to read than to take anybody's word for it, myself included.

MADDSLOW

iTrader: (11)

As I mentioned earlier, my FD is running 21psi on a *safe* tune. IMO, having the ability to have an extra map tuned to 28psi to use with the Toluene on rare track days outweighs the long-term risks of repeatedly using it.

If Toluene was something I planned to use every day, I could see how the repeated contact with it could be alarming. But carefully and properly adding it a few times a year isn't enough to worry me.

RotaryEvolution

iTrader: (30)

NOx and carbon monoxide are toxic emissions that your catless car puts out whenever it is running. so i don't understand why it would even be brought up.

a long time ago we used to run leaded fuels, lead is probably one of the leading carcinogens out there and i don't recall the population keeling over from it.