Hazardous Materials (HAZMAT) are everywhere and in many, and, probably in most, cases those being exposed are completely unaware of their presence. They are almost totally unaware of their identity or the nature of the hazard. Most chemicals are not benign and this includes pharmaceuticals which almost invariably have some potential for adverse side effects. 

See for examples: The People's Pharmacy

Also, for regular bulletins from Chemicals Health Monitor Electronic Bulletin – Resources on Chemicals and Health, see  Health And Environment Alliance                     

To a somewhat lesser degree, herbal remedies and dietary supplements can pose health risks along with their benefits. Unfortunately the controls over exposure and use of chemicals have fallen far short of being optimum. This has been clearly demonstrated to be the case in China as well as in North America. The average consumer has received little training regarding the use of Material Safety Data Sheets (MSDS). Volunteer fire fighters often fall into this group. We strongly urge everyone given the opportunity to learn more about HAZMAT and MSDS to do so. Inexpensive booklets are available from Genium and are highly recommended to Canadians and Americans. They are written in very understandable language.

When it became obvious that almost all students at an Midwestern American university lacked such training and there were both safety and liability issues involved, 14 hours of instruction became a mandatory requirement for all students who would take laboratory courses and all employees. Even secretaries handle HAZMAT on a daily basis.

Fire fighters will most surely be exposed to HAZMAT when fighting fires. That is one of the reasons they have special gear, including self contained breathing apparatus (SCBA or BA). With motor vehicle accidents (MVA) there is potential exposure from spillage and fire. When transport trucks are involved, the recommended procedure is to check for placarding using binoculars and to then consult the Emergency Response Guidebook for cautions and recommendations. In some instances these may include clearing an area over 2 kilometer in radius and not approaching the accident without proper HAZMAT gear. With explosives the recommendation is often to not fight the fire. For passing motorists, our recommendation is to keep clear if there is orange or yellow placarding, a skull and crossbones on the placard or a white radioactive placard. Compressed gases, both green placard and red placard, also pose considerable risks in case of fire. If the road is obstructed, do a U-turn and leave. Do not wait for the arrival of emergency vehicles. LEAVE! If you are between exits 17 and 17a on Highway 103, visit Greenfield. Do not duck through Mill Village unless directed to do so by traffic control personnel. Unless specifically directed by traffic control people, avoid bypassing through Danesville on Highway 3 to get around a bad scene on that stretch of the 103. The two roads are not that far apart.

PLACARDS

Placards are supposed to alert everyone with access to a copy of the “Emergency Response Guidebook” as to the potential dangers associated with the cargo so labeled. As the song says: “it ain’t necessarily so.” The compound ammonium nitrate is known to undergo explosive degradation with mass fragmentation but is placarded as oxidizer 5.1 (yellow placard, rather than explosive 1.5 orange placard). Although the Guidebook admits the potential, the yellow placarding can lull one into a false sense of security. It has been argued that the reason for yellow placarding lies in the associated transportation cost for ammonium nitrate fertilizers. Based upon the redactors experience in the use and manufacturing of explosives and propellants and discussions with similar individuals, he recommends that all yellow placard (oxidizer) situations be treated as potential Explosive Class 1.1. The argument here is fairly simple. Mixed explosives with two or more components are usually mixes of oxidizers and fuels. With a vehicle fire one obviously has satisfied the fire triangle of need for, heat, oxygen and fuel. With an additional oxidizer source things can be expected to take off. With pure ammonium nitrate, fast heating can cause an explosion without any fuel. (Bundesanstalt fuer Materialpruefung (BAM)). J. Koehler u. R. Meyer, Explosivstoffe, VCH, Weinheim, 1991.    

        See also: BBC Edited Guide Entry

  EnvironmentalChemistry.com 

  IanAlbert.com

You will note that all placards shown are displayed with the diamond configuration with a point being the base. Within the base point is a single numeral with a value of from 1 to 9 which is the hazard class.

1 = explosive, 2 = compressed gas, 3 = flammable liquid, 4 = flammable solid, 5 = oxidizer, 6 = poison, 7 = radioactive, 8 = corrosive liquid, 9 = miscellaneous.

The choice of class is not arbitrary, but rather it is based on what is considered the most important property in case of an accident and/or spill.

The colour of the placard is more arbitrary.

Class 1 placards are unique in that all members of the class are explosives.

The sub-categories of explosives are not arbitrary. They reflect careful testing of the materials using internationally accepted protocols and apparatus developed in part by government testing laboratories. Those of the German group BAM furnish readily reproducible statistics. The tests include impact sensitivity (drop weight), friction sensitivity which measures torque, velocity, and force, spark which measures voltage and energy, and heat which measures rate of heating and confinement of the sample. However, it is the redactor's recommendation that in accident and fire situations, all Class 1 materials be treated as Class 1.1

Class 2 placards may be green (non-flammable), red (flammable), yellow (oxygen pressurized or liquid), white (toxic, compressed gas).

Class 3 placards are red and encompass flammable liquids.

Class 4 placards have alternate vertical red and white bars for flammable solids (4.1), upper half white, bottom half red, spontaneous combustible (4.2), all blue, dangerous when wet (4.3).

Class 5 placards are yellow, with 5.1 being labeled oxidizer and class 5.2 abeled organic peroxide. One of the explosives favored by terrorists, diacetone peroxide is a member of this class of molecules. Both Classes 5.1 and 5.2 may be placarded without the words oxidizer or organic peroxide.

Class 6 placards are health related and white. They may exhibit a skull and crossbones, the words inhalation hazard, or poison, or toxic, or an ear of corn with an X across it, with or without the warning, stow away from food stuffs. Class 6 also includes biohazards.

Class 7 has a yellow top triangle and a white base triangle. Within the yellow will be the familiar radioactive symbol and the white may contain the words radioactive.

Class 8 placards are black bottomed and white topped with a picture of a hand and a metal plate being attacked by a corrosive substance.

Class 9 seems to have no name but it has a white bottom topped by black and white bars. The response guide has the caption: low to moderate hazards.

In addition to the square diamond placard there may often be a group of 4 digits across the placard. You may have noted red placards with the numbers 1202 (kerosene), 1203 (gasoline) and 1993 (Diesel fuel).

MSDS

Introduction:

Material Safety Data Sheets are divided into 9 sections. These range from Material Identification through Special Precautions and Comments. Since we have already introduced ammonium nitrate, we will use the MSDS for Ammonium Nitrate for our discussion example. All MSDS are supposed to have the following contents.

Table of Contents

Section 1. Material Identification

Section 2. Ingredients and Occupational Exposure Limits

Section 3. Physical Data

Section 4. Fire and Explosion Data

Section 5. Reactivity Data

Section 6. Health Hazard Data

Section 7. Spill, .Leak and Disposal Procedures

Section 8. Special Protection Data

Section 9. Special Precautions and Comments

Sample MSDS:    Click here to view a sample MSDS.

Section 1. Material Identification

In this section we encounter the Fire Diamond which provides a visual system furnishing a general idea of the inherent hazards, and their severity, of materials relating to fire prevention, exposure and control. The reading order is A> Health, B> Flammability, C> Reactivity,

D> Special. The Diamond, setting on its point, is divided into four smaller diamonds beginning at the nine o’clock position and proceeding clockwise from A through D.

Position A - Health Hazards (blue), degree of hazard; level of short term protection. Level:

0 = ordinary combustible hazard in a fire
1 = slightly hazardous
2 = hazardous
3 = extreme danger
4 = deadly

Position B - Flammability (red), susceptibility to burning

0 = will not burn
1 = will ignite if preheated
2 = will ignite if moderately heated
3 = will ignite at most ambient conditions
4 = burns readily at ambient conditions

Position C - Reactivity, instability (yellow), energy released if burned, decomposed or mixed

0 = stable and not reactive with water
1 = unstable if heated
2 = violent chemical change
3 = shock and heat may detonate
4 = may detonate

Position D Special hazards (white)

OX = oxidizer

W = use no water, reacts!

For the case of ammonium nitrate we see that, in the case of fire, it is hazardous with shock and heat when it may detonate. Under all conditions it is an oxidizer. 

Section 2. Ingredients and Occupational Exposure Limits.
We see that no limits had been established except for rats.

Section 3. Physical Data.
We see that ammonium nitrate is hygroscopic (attracts moisture) and clumps (see redactors comments).

Section 4. Fire and Explosion Data.
Note that firefighters should use SCBA and if large amounts of ammonium nitrate are involved a monitor nozzle should be employed and fire fighters should move to a safe (undefined) distance.

Section 5. Reactivity Data.
Note the large selection of substances which react violently with ammonium nitrate.

Section 6. Health Hazard Data.
Note that it is not all that benign.

Section 7. Spill, Leak and Disposal Procedures.
Note that there are fairly extensive regulations regarding disposal of what is often just fertilizer.

Section 8. Special Protection Data.

This is a general collection of common sense practices applicable in most situations.

Section 9. Special Precautions and Comments.
In general more common sense, except that wooden pallets for storage of oxidizer is a poor selection.

Redactors Additions:

Ammonium nitrate is not particularly hygroscopic. It forms clumps because at and around room temperature it undergoes phase changes from one solid form to another. These have differing specific volumes and tend to fill void spaces and form new crystals from the old. It is quite likely that this along with some moisture was the primary contributor to the formation of the solid masses of ammonium nitrate/ammonium sulfate that exploded at Oppau, Germany. The problem is sufficiently severe that prills for use in fertilizer and ammonium nitrate-fuel oil explosives are treated with a fine dusting of diatomaceous earth.

Useful websites:

http://www.tc.gc.ca/canutec/en/GUIDE/guide.htm

http://www.chrismanual.com/

http://www.chemtrec.com/Chemtrec/

Http://www.nrc.uscg.mil/nrchp.html

Although the Emergency Response Guide Book is heavily American in origin, references and slant, it is a joint American, Canadian and Mexican product. The emergency support information for accidents involving hazardous materials CHEMTREC and the National Response Center (NRC) are located in the USA. . NRC is operated by the U S Coast Guard which is part of the US Department of Transportation.  Much of the supporting material for CHEMTREC and NRC can be found in a voluminous collection of data sheets maintained by the Coast Guard and available to the public called Chemical Hazardous Response Information System (CHRIS). This tome comes in two printed forms; a 6 inch thick, printed on both sides, 8 ½ by 11 inch paper, loose leaf format, CHRIS and a smaller condensed guide of CHRIS (4½ by 6 inch) also published as loose leaf and 2½ inch thick.  There is also a computer readable form (Adobe Acrobat).  The type script of the paper copies requires good light and a magnifying glass to read.  Critical information is printed in red.  The involvement of the Coast Guard is logical since they have jurisdiction over navigable waters and much of the information in CHRIS is related to water pollution.  For demonstration purposes we will use ammonium nitrate. CHRIS sheets have a set format and some of the entries are similar.

The entries of the two for other names or synonyms is striking since the MSDS lists two and CHRIS list only one (Nitram, not found on the MSDS) and both miss the abbreviation AN which is universally used in the explosive industry and by its users in explosives.

The first red letter entry is “call fire department, keep people away, evacuate area in case of large discharge, isolate and remove discharged material. Notify local health and pollution authorities.”  The second red letter entry follows under the Fire entry and reads “Wear self contained breathing apparatus. Evacuate surrounding area. Combat fire from protected location with unmanned hose holder or monitor nozzle. Flood discharge areas with water. Cool exposed containers with water. Continue cooling after the fire has been extinguished. “

The section on exposure is fairly general and water pollution is in red since it is a dangerous contaminant for humans and wild life.  All of the above is found in introductory sections.  There follows, twelve sections which are followed by a full sheet of more information for Section 12, covering heat capacity, solubility, vapor pressure, vapor density, all as functions of temperature.

Section 1:     Response to discharge;

Section 2:     Label (placard), oxidizer, Class 5;

Section 3:     Chemical Designation;

Section 4:     Observable characteristics;

Section 5:     Health hazards;

Section 6:     Fire hazards;

Section 7:     Chemical reactivity,

Section 8:     Water pollution,

Section 9:     Shipping information,

Section: 10:  Hazard Assessment Code,

Section 11:   Hazard Classification (see treatment of Fire Diamond in MSDS Section);

Section 12:   Physical and chemical properties 

From the above, we hope it will be recognized that in case of an emergency, call CHEMTREC (collect, 202-483-7616) or NRC.  Their lines are available 24 hours a day, 7 days a week., 365 days a year.  They can also be accessed by computer queries through their web sites.

DoD Contractors' Safety Manual for Ammunition and Explosives:

http://www.stormingmedia.us/34/3451/A345143.html

The DoD Manual provides very careful analyses of Hazard Class 1 (explosive) materials as well as directions for safe usage and storage.  It is sufficiently detailed as to deal with situations where a munition does not fire or explode (hang fire or missfire).  

Exposure to Asbestos:

Exposure to asbestos can cause a disease called mesothelioma.  See: