Sunday, 11 September 2011

Toxicity of different chemicals

Again, I'm writing this one to create awareness among students and those who are working in the chemistry lab. Sadly, they do not know seriousness of using some toxic chemicals and its health effects. I hope this post is very useful for them and they can know how to handle these toxic chemicals. The below list will tell you what you should do and what should not:

1.   Lithium and its compounds: Lithium metal should be handled carefully as it reacts with water violently. In case of lithium compounds, it is wise to avoid them as they affect the central nervous system.

2. Fluorine and Fluorides: Fluorine is the most reactive element known. It reacts with most of the elements violently. Even chemists do afraid to handle Fluorine. So, It should be handled with utmost care. Fluorides will release very toxic and corrosive hydrogen fluoride on adding concentrated sulphuric acid.

3. Sodium and its compounds: Elemental sodium possess fire hazard as it reacts with water almost explosively. So, extreme care should be taken while handling Sodium metal. Most of the sodium compounds are safe to use. But, there are some exceptions - Sodium cyanide, Sodium azide, Sodium chromate etc.. Here you see the toxicity mainly depends upon the anions present in it.

Sodium metal under paraffin oil

4. Magnesium and its compounds: Magnesium possess fire hazard as it burns in the oxygen violently. It is hard to distinguish magnesium fire. Also, it produces harmful ultraviolet rays when burning. But, it won't be a problem if you handle it carefully. Magnesium compounds are safe to use.

Magnesium ribbon

Anhydrous aluminium chloride
5. Aluminium and its compounds: Do not possess significant health hazard. But, you should know the reactivity of Aluminium before you use it as it reacts with some elements violently. For example: Bromine, Chlorine etc....

6. Phosphorus and its compounds: We all know white phosphorus possess significant fire and health hazard. It should be kept under the water since it reacts with atmospheric oxygen violently and produces clouds of phosphorus pentoxide. As far as red phosphorus is concerned, it is lot safer to use compare to white phosphorus. It is not pyrophoric  like white phosphorus. Oxides of phosphorus and phosphine should be avoided as they will affect our health significantly.

7. Sulphur and its compounds: Elemental sulphur is not toxic. But, it possess fire hazard when it mixes with strong oxidizing agents like potassium chlorate. Sulfur compounds are toxic especially those are in gaseous phase. For example: Hydrogen sulphide, sulfur dioxide etc....

Elemental sulphur

8..Chlorine: Chlorine is highly toxic and it will cause serious damage to our lungs even if you inhaled for few minutes.

9. Potassium and its compounds: Again, Potassium possess significant fire hazard as it reacts with water explosively. It should be handled under expert supervision. Like sodium compounds, the toxicity mainly depends upon the anions present in it. Otherwise, they are safer to use.

10. Calcium and its compounds: Albeit, Calcium metal does not react with water violently like alkali metals, care should be taken. Calcium compounds are pretty benign and safer to use.

11. Chromium compounds: Chromium compounds are extremely toxic. Especially, hexavalent chromium compounds are carcinogenic (will cause cancer) on chronic exposure. Also, they are strong oxidizing agents. They react violently with strong reducing agents. Sadly, some will cause reproductive defects. Eg. Potassium chromate. They are also very dangerous for the environment. But, people love chromium compounds as they are very colorful.

12. Manganese compounds: Not possessing significant health hazard. Anyway, chronic exposure should be avoided.

Manganous sulphate

13. Iron compounds: Safe to use.

Ferrous oxalate

14. Cobalt compounds: Dangerous for the environment and extremely toxic. An animal carcinogen.

15. Nickel compounds: Dangerous for the environment and extremely toxic. Chronic exposure will cause cancer. May cause allergic reaction to the skin on contact.

16. Copper compounds: Toxic but manageable.

17.Zinc compounds: Toxic but manageable.

18. Arsenic and its compounds. Extremely dangerous for the environment and will cause cancer even on few exposure. Significant health hazard and will lead you to death.

19. Bromine and bromides: Bromine is highly toxic and will cause damage to our respiratory system. Also, it is very corrosive and will cause burns. It will react violently with some metals.

Bromine in sealed ampules
Bromides will release toxic bromine and hydrogen bromide on adding concentarted sulphuric acid.

Strong bromine water

20. Silver compounds: Not possess serious health hazard.

21. Cadmium compounds: Extremely dangerous for the environment and will cause cancer even on few exposure. Significant health hazard and will lead you to death.

22. Tin compounds: Moderately toxic but manageable.

Stannous chloride

23. Antimony compounds: Dangerous for the environment and extremely toxic.

24. Iodine and Iodides: Toxic on ingestion. Do not inhale iodine vapor much. Overall toxicity is less compare to bromine and chlorine. Again, Iodides will release a mixture of Iodine & Hydrogen Iodide on adding concentrated sulphuric acid.


25. Barium compounds: All are extremely toxic except Barium sulphate since it is completely insoluble in water. Barium compounds will cause lung disease and other serious concerns. If a person suffering from Barium poisoning, it is wise to give sodium or magnesium sulphate solution to the victim. Once the victim drink that solution, non toxic barium sulphate is precipitated and it will be eliminated completely from the body.

Barium sulphate

26. Mercury and its compounds: Cumulative poison. Mercury and its compounds are extremely toxic. Hence, they should not be released to the environment.

27. Lead and its compounds: Extremely toxic and possess serious health risks. Cumulative poison. Lead compounds will target almost all the organs in our body and will lead to death on chronic exposure. As there are many risks involved with lead compounds, they should not be released to the environment.

28. Ammonia and its compounds: Ammonia is moderately toxic. It will be fatal after a few deep breaths of the gas. Its compounds have a  low to moderate level of toxicity. Not a serious health concern in overall picture.

I always believe it is wise to avoid compounds which possess extreme health hazard and also dangerous for the environment as we do not have proper disposal facilities and need of very good lab facilities. Also, these will affect our health significantly even on inhalation. But, we cannot deny the fact that every chemical has tonnes of uses albeit some are very toxic.

You can write your comments on my post and I will help you if I can :)


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