1. درس ایمنی در آزمایشگاه
جلسه ششم
مدرس:
ابوالفضل بضا عت پور 1

2. خطرات فیزیکی مواد شیمیایی(Physical Hazards of Chemicals)
Flammable Š&combustible
Oxidizer
Water-reactive
Pyrophoric
Shock-Sensitive and Friction-Sensitive xplosives Š
Compressed gas
Cryogenic Liquids

3. Cryogenic Liquids مایعات برودتی
A cryogenic liquid is a liquid with a boiling point that is less than or equal to -90 oC at (1 atm) pressure.
Cryogenic fluids, such as liquid air, liquid nitrogen, or liquid oxygen, are used to obtain extremely cold temperatures.
Most cryogenic liquids are odorless, colorless, and tasteless
Cryogenic liquids can cause
fires (e.g., liquid oxygen or liquid hydrogen)
Explosions
embittlerment of structural materials
Asphyxiation
tissue destruction

4. Review Questions
A flammable liquid will emit enough vapors to be ignited by a spark source at temperatures:
a. above absolute zero
b. above 22 °C (70 °F)
c. below 38 °C (100 °F)
d. above its freezing point

5. A flammable liquid will emit enough vapors to be ignited by a spark source at temperatures:
a. above absolute zero
b. above 22 °C (70 °F)
c. below 38 °C (100 °F)
d. above its freezing point

6. Cryogenic liquids can:
a. displace air in a lab
b. freeze skin
c. embrittle materials
d. explode
e. all of the above

7. Cryogenic liquids can:
a. displace air in a lab
b. freeze skin
c. embrittle materials
d. explode
e. all of the above

8. خطرات سلامتی مواد شیمیایی Health Hazards of Chemicals
راههای ورود مواد Routes of Entry
فاکتورهای در معرض خطر قرار گرفتنToxic Exposure Factors
نوع خطر Types of Health Hazards
خطرات درکمین دستگاه تناسلی Reproductive Health Hazards
مواد مضر ویژه Particularly Hazardous Substances

9. راههای ورود مواد Routes of Entry
استنشاق Inhalation (آستانه بو)
تماس چشم و پوست Skin and Eye Contact
rinse the affected area with water for at least 15 minutes
خوردن Ingestion
Ingestion can occur by failing to wash hands before eating or drinking, eating or drinking contaminated food or beverages in the work area, or touching the mouth with contaminated hands. Workers can easily reduce the risk of ingestion by not eating, drinking, smoking
تزریق Injection
Another possible route of exposure to chemicals is by accidental injection which can occur by needle sticks or through accidents with broken glassware or other sharp objects that have been contaminated with chemicals.

10. فاکتورهای در معرض خطر قرار گرفتنToxic Exposure Factors
نوع و مقدار در معرض قرار گرفتن Type and Magnitude of Exposure
سمیت حاد Acute toxicity : مسمومیت سریع در اثر قرار گرفتن در معرض شدتهای کوتاهی از مواد شیمیایی مانند Hydrogen cyanide, hydrogen sulfide, nitrogen dioxide, ricin, organophosphate pesticides and arsenic میباشد
سمیت مزمن : Chronic toxicity : قرار گرفتن مداوم در معرض مقادیر کم در مدتهای طولانی باعث این مسمومیت میشود مانند Mercury, lead, and formaldehyde
حساسیت فردی Individual Susceptibility
بعضی افراد وابسته به جنسیت، سن، عادات غذایی، شرایط فیزیکی، چاقی و لاغری، شرایط داروییف بارداری و ... میتوانند عکس العمل متفاوتی را در مواجهه با مواد شیمیایی مختلف از خود نشان دهند که به آلرژی یا حساسیت معروف هستند مانند نمکهای نیکل و تیتانیوم ، رزینهای اپوکسی و ایزو سیانید و فروآلدهِیدو...
طبقه بندی فیزیکی عوامل Physical Class of Agent
مواد با حلالیت بالا در قسمت فوقانی دستگاه تنفسی اثر میگذارد مثل آمونیاک و مواد نا محلول مانند NO2 در عمق ریه نفوذ میکنند. ذرات گرد و غبار آلوده با قطر بیش از 1 میکرو متر در دستگاه فوقانی و کمتر از آن در ریه نفوذ میکنند

11. نوع خطر Types of Health Hazards
حسا سیت و آلرژی Allergens and Sensitizers
بی حس کنندگی اولیه Primary Anesthetics
سمیت خونی Blood (Hematopoietic) Toxins
مواد سرطانزا Carcinogens
مواد خورنده Carcinogens
سمیت زیست محیطی Environmental Toxins
سمیت کبدی Hepatotoxic Agents
محرکها Irritants
سمیت ریوی Lung (Pulmonary) Toxic Agents
سمیت کلیوی Nephrotoxic Agents
عوامل عصبی Neurotoxic Agents

12. حسا سیت و آلرژی Allergens and Sensitizers
Allergens and sensitizers include a variety of substances capable of producing skin and lung hypersensitivity. Examples of common substances include:
epoxides,
nickel compounds,
poison ivy,
toluene diisocyanate and other isocynates,
chlorinated hydrocarbons,
chromium compounds (i.e., chromates),
formaldehyde,
amines
certain phenols.

13. بی حس کنندگی اولیه Primary Anesthetics
Primary anesthetics have a depressant effect upon the central nervous system, particularly the brain. Examples include:
diethyl ether,
alcohols
halogenated hydrocarbons (chloroform, trichloroethylene, carbon tetrachloride).

14. سمیت خونی Blood (Hematopoietic) Toxins
Some toxic agents can damage blood cells or hematopoietic system (e.g., bone marrow). Examples include:
nitrites,
benzene,
toluidine,
aniline
nitrobenzene

15. مواد سرطانزا Carcinogens
A carcinogen is any substance that contains an agent that can initiate or speed the development of malignant or potentially malignant neoplastic proliferations of cells (i.e., causes cancer). Many chemicals have been evaluated for their ability to cause cancer. It is believed that these carcinogens directly or indirectly interact with cellular DNA causing permanent alterations.
PDF

16. مواد خورنده Carcinogens
A corrosive is a chemical that can cause visible destruction of or irreversible alterations in living tissue by chemical action at the site of contact. Corrosives can also react (e.g., oxidation) with metals causing deterioration of the metal surface. Acids and bases are corrosives. Aqueous solutions of acids with a pH less than 2, and bases with a pH greater than 12 are especially dangerous and require special precautions. Examples of common corrosives are:

17. سمیت زیست محیطی Environmental Toxins
Some chemicals are or may be very toxic to wildlife or can otherwise harm ecosystems but pose less risk to humans. Some factors contributing to environmental toxicity are persistency (resistance to degradation) and bioaccumulation as the chemical moves up the food chain. For some environmental toxins the degree of human toxicity is uncertain or controversial. DDT and polychlorinated biphenyls (PCBs) are examples of chemicals that have been shown to cause reproductive failure in certain species but appear to be less hazardous to humans.

18. سمیت کبدی Hepatotoxic Agents
Hepatotoxic agents cause damage to the liver. Examples include:
carbon tetrachloride,
nitrosamines,
1,1,2,2-Tetrachloroethane

19. محرکها Irritants
Irritants are substances that inflame mucous membranes when they come in contact with these membranes. The inflammation occurs at concentrations far below those needed to cause tissue destruction. Chronic exposure to irritants can cause increased mucous secretions and result in chronic bronchitis. Commonly encountered irritants include:

20. سمیت ریوی Lung (Pulmonary) Toxic Agents
Some agents cause damage to the pulmonary tissue (lungs) by means other than immediate irritant action. Fibrotic changes can be caused by free crystalline silica and asbestos. Other dusts (e.g., coal dust, cotton dust, wood dust and talc) can cause a restrictive disease called pneumoconiosis.

21. سمیت کلیوی Nephrotoxic Agents
Nephrotoxic agents damage the kidneys. Examples include:
halogenated hydrocarbons
uranium compounds.

22. عوامل عصبی Neurotoxic Agents
Neurotoxic agents can damage the central or peripheral nervous system. The nervous system is especially sensitive to organometallic compounds and certain sulfide compounds Examples of neurotoxic agents include:
Š trialkyl tin compounds
Šmethyl mercury Š
tetraethyl lead
carbon disulfide
Šthallium Š
manganese Š
organophosphate insecticides

23. پایان جلسه ششم 23