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How toxic is toxic?

Chemicals may cause harm in many different ways. They may be flammable, explosive, radioactive, corrosive, etc. All chemicals are toxic at some level. The dose, however, determines the hazard. Every chemical has some set of exposure conditions in which it is toxic and, conversely, every chemical has some set of exposure conditions in which it is not toxic. Therefore, before beginning to work with a chemical, we must understand how it can affect us and at what dosage.

Toxicologists are scientists who study how chemicals cause damage to living tissues. Many methods have been developed to determine the toxicity of chemicals. Acute toxicity, which is defined as the immediate effect of a substance as a result of a single dose, is relatively easy to study. Chronic toxicity, which results from low doses of a chemical repeated over long periods of time, is much more difficult to test.

Toxicity is objectively evaluated on the basis of test dosages made on experimental animals under controlled conditions. The most common measure that toxicologists use to estimate the acute toxicity of chemicals on humans is LD50. LD50 is an abbreviation for “Lethal Dose 50%.” The LD50 value for a chemical is the amount of chemical that can be expected to cause death in half (50%) of a group of a particular animal species when the chemical enters the body by ingestion or skin absorption. The amount required to cause death is normally related to body weight: therefore, the LD50 is expressed in milligrams of chemicals per kilogram of body weight (mg/kg). A typical LD50 statement includes the substance, the route of entry, and the animal species; as shown below:

Aniline LD50 oral-rat: 250mg/kg.

In plain English, this LD50 statement says that a single oral dose consisting of 250 mg of aniline will kill, on average, one-half the population of 1-kg rats.

It should be noted that no LD50 data exists for humans. Data from test animals is used to estimate the possible acute toxicity of a chemical on a human being. Toxicity, data should therefore be used to evaluate the relative toxicity of various chemicals and which chemicals may require greater precautions when handled. The lower the LD50 value, the more toxic the substance. Refer to the chart in the Laboratory Safety Article section of the Flinn Scientific Catalog/Reference Manual for: LD50 values for many common chemicals found in high school chemistry laboratories. LD50 values have not been measured for all chemicals – even some known hazardous chemicals such as lead compounds, do not have known LD50 values.

In general, chemicals with LD50 values less than 300mg/kg are considered highly toxic, those with LD50 values between 300 and 1,000 mg/kg are considered moderately toxic, and those with LD50 values between 1,000 and 5,000 mg/kg are considered slightly toxic. Because LD50 values depend on body weight, however, many chemicals that may not harm an adult may be toxic to a small child.

WARNING

Never, ever consume any laboratory chemicals. The LD50 value is an approximation, relative acute toxicity value based on statistical calculations.

Some people may become severely ill or even die at much lower dosages than an LD50 may suggest.

Flammable and combustible liquids

This section will give you a better understanding of flammables and combustible liquids.

The storage, use and disposal of flammable and combustible liquids falls under the rules and regulations promulgated under OSHA, and the National Fire Association.

All users of flammable and combustible material must follow these rules.

A flammable liquid is any liquid, solid or gas that will ignite easily and burn rapidly. Materials that are flammable are of concern due to their ability to render damage to property and more importantly, to injure or cause death of workers.

“Flammable liquids” refer to any liquid having a flash point below 100°F. Such flammables are Class I liquids. These liquids are subdivided onto three classes. The following is an illustrative list of common flammable liquids:

Class IA Flash point below 73°F, boiling point below 100°F

acetaldehyde	ethyl chloride	petroleum ether
collodion	methyl ethyl ether	propylene oxide
ethyl ether	pentane

Class IB Flash point below 73°F. boiling point at or above 100°F

acetone	ethyl acetate	methyl alcohol
benzene	ethyl alcohol	methycyclohexane
butyl alcohol	gasoline	toluene

Class IC Flash point at or above 73°F and below 100°F

amyl acetate	isopropanol	turpentine
amyl alcohol	methyl alcohol	xylene
dibutyl ether	styrene

“Combustible liquids” refers to any liquid having a flash point at or above 100°F. Combustible liquids are subdivided as follows:

Class II Flash point at or above 100°F and below 140°F

acetic acid	fuel oil no. 44	mineral spirits
camphor oil	methyl lactate	varsol
cyohexane	hydrazine	kerosene

Class III Flash point at or above 140°F and below 200°F

anline	furfury alcohol	phenol
carbolic acid	naphthalenes	pine oil

EPA set to inspect K-12 schools

The Environmental Protection Agency plans to inspect K-12 schools to determine if they comply with safe storage and handling of chemicals. These visits will be unannounced so schools need to be aware of a possible visit at any time.

An EPA official said: “High Schools should be aware that mismanagement of their chemicals and waste may harm students, staff and faculty - they may also be in violation of EPA regulations that could result in enforcement actions with penalties.

Colleges in the state have been under inspection for some time. Dangers include chemicals stored in back rooms and closets and then forgotten. The EPA will be looking at improper use, storage and disposal of:

• Chemicals, computer and electronic equipment;
• Fluorescent lamps and other mercury-containing equipment;
• Picric acid, ethers and sodium metals.
  

For general information, see www.epa.gov/schools

Mercury removal

BY LAW ALL MERCURY MUST BE REMOVED FROM OUR SCHOOLS! This includes globe program equipment, spectrum tubes, thermometers, barometers, BP kits and liquid mercury. If your school still has mercury please fill out a separate chemical removal form (PO18), which can be obtained the Lab Specialist Forms page, and submit it to your custodian. If you do not hear anything in two weeks please call Ms. Pedram at 718-361-3701.

Removal Procedures for Mercury & Mercury containing products/equipment

1. Inventory:
   During the course of your annual chemical inventory make special note of any elemental mercury in your storage areas. Look for glass jars, bottles, vials that may contain mercury.
   During the course of your annual equipment inventory make note of thermometer, barometers, hygrometers, vacuum gauges, steokel tubes, sling psychrometers, gas law apparatus, anemometers, blood pressure equipment – that may contain mercury.
2. Make note on the inventory form of the number/amount of items, location (room, cabinet, drawer etc), number of non-mercury replacements needed, tag or identify the items with an obvious marking
3. Complete the chemical removal form. Be sure to include all necessary information. Make a copy for your administrator and keep a copy for your records .
4. Pass the completed form on to your principal, administrator or custodian for processing.
5. * Do not move or remove mercury containing items yourself – the professional removal company will do this.

It is imperative that we remove all mercury and mercury containing equipment from our schools. If you need me to expedite removal please contact me at 212-598-7764 or email me at lcampetellauft@yahoo.com. Your cooperation in removing all mercury is greatly appreciated.

SAFETY: Check out the Flinn catalog, page 996. Flinn offers an inexpensive fire extinguisher powder for Class D fires. Catalog # SE3004 500gr bottle for $13.40. If you have metals and do not have a Class D fire extinguisher this is a great alternative.

EMERGENCY PROCEDURE: Don’t wait for an emergency to happen. Be Prepared. Have emergency phone numbers posted for easy access. At our January training special fill-in forms were distributed for such use. Have spill kits ready and handy. Have signs made in advance “ROOM CLOSED”. Hopefully, you will not need them but if you do you will be prepared.

EDUCATORS' TAX DEDUCTION: Lab Specialists are entitled to claim a $250.00 deduction on their federal tax returns for out- of-pocket expenses that have not been reimbursed. This includes books, supplies, equipment and supplementary materials that are used in the school. This deduction does not need to be itemized and can be made on the 1040E-Z for or on Form 1040 line 23.

METHANOL ACCIDENTS: Countless, unnecessary lab accidents have occurred throughout the years using methanol as a solvent to demonstrate various colors of metal salts. Students and teachers have suffered third degree burns over a large portion of their bodies as a result.

Always remember to use safer substituions when possible in doing experiments. Instead of using Methanol the same results can be achieved by mixing the salts into tiny beads of melted borax at the end of a platinum wire and putting the bead in a flame. No flammable solvents were used. No danger to student and staff.

HR CONNECT: 718-935-4000 is the place to call to report any change in personal status such as address, phone number and marital status.

BOOK BUY BACK PROGRAM: The Department of Education has partnered with two companies to facilitate the process of removing obsolete textbooks from our schools. The vendor will remove both books with value and those that have no value. The later will be recycled. This will enable the schools to receive financial compensation for obsolete books that have resale value and re-claim space. The vendors are Budgettext and Follett Educational Services. Schools have to list textbooks on the FAMIS Portal in the inventory section under miscellaneous option. Click on its Book Buy Back Program and enter the list of materials. This list will then be sent to the appropriate vendor for notification. The process will take two visits. One is an Assessment visit and the second is the Book Pick Up Visit.

CHEMICAL INVENTORY: A separate listing for Flammables and Combustibles is now required by the NYC Fire Department. This year when doing your inventory put all Flammables on one sheet(or several sheets) and label it “FLAMMABLES”, the Combustible on another sheet(or several sheets) and label it ”COMBUSTIBLES” and the remainder of your inventory on separate sheets.

HUMAN SPEICMEN DISPOSAL: In order to dispose of human specimens you must label it as “HUMAN TISSUE” for it to be picked up.

RIGHT TO KNOW: Posters for “Laboratory Safety and Health Standards”, “Bloodborne Pathogens Standards” and “Hazard Communication Standard/Right to Know Law” can be found at the DOE Office of Occupational Safety and Health. They can be printed out, filled out and posted in your schools.

SMOKING CESSATION: The UFT is offering a SMOKING CESSATION program to its members free of charge. Call the Smoking Cessation Helpline at 212-598-7763 between 10am to 6pm. Come to the 52 Broadway office to pick up patches and get confidential assistance on how to quit smoking.

NEW MEMBERS: All new members to the system should enroll in the UFT and Welfare Fund as soon as possible.

New York Times article: “Drugs Are in the Water. Does It Matter?”

One of the topics at our Health and Safety training sessions is the safe disposal of chemicals.

At our Bronx Training the question of proper disposal of outdated or unused drugs was raised. There was concern because traces of most commonly used drugs are showing up in our nations waterways.

The NT Times article discusses this phenomena and some methods used to destroy the drugs, such as, mixing with cat litter or dissolving in water. In the end those things are discarded, taken to landfills and wind up leaching into the waterways.

The article goes on to state communities are setting up “pharmaceutical take back locations” in drug stores or police stations (for controlled substances).

So for all of us who are concerned about our environment and safe drinking water I suggest if you have any unused or outdated medication inquire in your community (local pharmacy or police station) where you can safely dispose of them.

The UFT Welfare Fund reminds us that unused or outdated medications can be returned and that company uses a third party to destroy them.

We should all continue our vigilance for safety and the removal of mercury in our schools.

Salmonella in Fish Tanks

New York Times article, dated April 18, 2006, stated fish owners beware. Researchers reported on cases of bacterial infections serious enough to send some children to the hospital with high fewer and bloody diarrhea. The infection stemmed from a multidrug resistant strain of Salmonella paratyphi B that was traced by DNA analysis to the fish tanks in the patients' homes.

The risk of catching salmonella bacteria from pet reptiles, chicks, ducklings and other animals has been widely recognized for decades. Although the number of salmonella outbreaks linked to pet fish and aquariums is relatively small and widely scattered we should all be aware of the dangers since most of us have aquariums in our schools.

The use of caution and common sense is suggested when working with fish and aquariums. Some suggestions given for handling fish and aquariums are: wash hands frequently with soap and water, clean the area and sink after working with a bleach solution, four tablespoons per liter of lukewarm water. It is even suggested to eliminate the replacement of one-third of the tank's water twice each month and to strictly follow the manufacturer's instructions regarding filtration.

We do not have to panic or remove all aquariums from our schools. We should just be aware and use common sense when handling fish and aquariums.