I want to thank Alan for his excellent answers. At first it sounded like people were asking about toxicity as if it could be measured by the LD & LC50s, which of course it can't. These test will tell you if it can kill or seriously damage animals (and presumably you) immediately by skin or eye contact, inhalation or ingestion. That's useful, but many carcinogens, including powdered asbestos, won't harm any animals in the two-week long LD & LC50 tests.
And the route it takes to get into your body is important. For example, ingesting mineral oil just gives you the Aztec two-step. Inhaling it can cause lipoid pneumonia and death. Local 802 in NYC had three cases at one time of this pneumonia in musicians in a Broadway show that was using too much theatrical fog!
So this toxicity question is far more complicated. And the most important thing to remember is only a tiny fraction of the chemicals you use have been studied for chronic hazards. CAS registered it's 50 millionth chemical on Sept 7, 2009. About 900 chemicals worldwide have been fully evaluated for cancer effects, and cancer is just one of MANY possible chronic outcomes. We know squat about most chemicals, even some common ones and many "natural" ones which should not be assumed safe.
This is why the EU's Precautionary Principle is so important. If you don't know what it will do to you long term, don't get into intimate contact with it. And many of you have students and workers who could be pregnant. These women should not be exposed to any chemical unless it has been determined that the substance cannot cause birth defects, fetal toxicity, developmental defects or delays, or a number of other complications. And that, my friends, is the case with just about ALL of the chemicals we use.
So turn on the hood and glove up. It's good lab practice anyway. The answer is simple: no one can be harmed by a chemical to which they were not exposed.
The cavalry is coming in the form of the Global Harmonization System for MSDSs (to be called Safety Data Sheets). GHS has already been adopted by the EU and proposed by OSHA for adoption here. This GHS SDS has a toxicity section with 10 blanks for assorted acute and chronic tests. When a test has been done, the data must be reported. When the test has not been done, the only acceptable answer in that blank is "no data available." We should soon be able to glance down the list and see which tests have been done and which not.
This SDS feature will make my training for Hazcom and the Lab Standard so much easier!
And hopefully, this also will end the manufacturer's practice of using misleading statements on their MSDSs. For example, they love to say their chemical is "not listed as a carcinogen by IARC, NTP or OSHA" which almost invariably means there is no data.
In a message dated 6/12/2010 6:18:11 AM Eastern Daylight Time, ahalltoxic**At_Symbol_Here**MSN.COM writes:
Are you asking about ACUTE toxicity? LD50's/LC50's/ED50's can basically only deal with this.
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