SOP for Chemical Safety in Laboratory

Standard Operating Procedure for Chemical Safety in Laboratory

Standard Operating Procedure for Chemical Safety in Laboratory

1.0 Purpose:

The purpose of this document is to lay down procedures for appropriate safety measures to be followed in the laboratory thus eliminating conditions that can cause accidents.

2.0 Scope:

This procedure is applicable to all activities which involve handling of Flammable/ Combustible, Corrosive, Carcinogenic and Toxic, Oxidizing, Reactive chemicals and compressed gases in the Quality Control Laboratory at [company name].

3.0 Responsibility:

To follow safety instructions: All personnel working in the QC laboratory. 

4.0 Definition:

Definitions and general information of different types of chemicals handled in the laboratory is given below.

Flammables/ Combustibles:

Chemicals which exist, in a liquid form at ambient temperatures, with sufficient vapor pressure to ignite in the presence of an ignition source are called flammable or combustible liquids (note that the flammable/combustible liquid itself does not burn; it is the vapor from the liquid that burns). “Flammables” generate sufficient vapor at temperatures below 100oF (37.8oC), whereas “Combustibles” generate sufficient vapor at temperatures at or above 100oF. Invisible vapor trails from these liquids can reach remote ignition sources causing flashback fires. In addition, these liquids become increasingly hazardous at elevated temperatures due to more rapid vaporization.

Corrosive chemicals:

Corrosives (liquids, solids, and gases) are chemicals that causes visible destruction of or irreversible alterations in, living tissue by chemical action at the site of contact. Corrosive effects can occur not only to the skin and eyes, but also to the respiratory tract through inhalation and to the gastrointestinal tract through ingestion. Corrosive liquids have a high potential to cause external injury to the body, while corrosive gases are readily absorbed into the body through skin contact and inhalation. Corrosive solids and their dusts can damage tissue by dissolving rapidly in moisture on the skin or within the respiratory tract when inhaled.

Carcinogen and Toxins:

Carcinogens are substance that either causes cancer in humans, or because it causes cancer in animals, is considered capable of causing cancer in humans. Toxins are chemicals which cause harmful effects upon exposure.

Oxidizing chemicals:

Oxidizing chemicals are chemicals that bring about an oxidation reaction. The oxidizing chemical may provide oxygen to the substance being oxidized or Receive electrons being transferred from the substance undergoing oxidation. The intensity of the oxidation reaction depends on the oxidizing-reducing potential of the material involved. Fire or explosion is possible when strong oxidizing chemicals come in contact with easily oxidizable compounds, such as metals, metal hydrides or organics. Because oxidizing chemicals possess varying degrees of instability, they can be explosively unpredictable.

 Examples of Oxidizing Chemicals

Gases: Fluorine, chlorine, ozone, nitrous oxide, oxygen

Liquids: Hydrogen peroxide, nitric acid, perchloric acid, bromine, sulfuric acid

Solids:  Nitrites, nitrates, perchlorates, peroxides, chromates, dichromates, picrates, permanganates, hypochlorites, bromates, iodates, chlorites, chlorates, persulfates

Reactive chemicals:

Reactive chemicals are substances that have the potential to vigorously polymerize, decompose, condense, or become self-reactive due to shock, pressure, temperature, light, or contact with another material. All reactive hazards involve the release of energy in a quantity or at a rate too great to be dissipated by the immediate environment of the reaction system, so that destructive effects occur.

Reactive chemicals include: 1) explosives, 2) organic peroxides, 3) water-reactive and 4) pyrophoric.


Cause sudden, almost instantaneous release of pressure, gas, and heat when subjected to sudden adverse conditions. Heat, light, mechanical shock, detonation, and certain catalysts can initiate explosive reactions. Compounds containing the functional groups azide, acetylide, diazo, nitroso, haloamine, peroxide, and ozonide are sensitive to shock and heat and can explode violently.

Organic Peroxides:

Contain an -O-O- structure bonded to organic groups. These compounds can be considered as structural derivatives of hydrogen peroxide, H-O-O-H, in which one or both the hydrogen atoms have been replaced by an organic group. Generally, organic peroxides are low-powered explosives that are sensitive to shock, sparks, and heat due to the weak -O-O- bond which can be cleaved easily. Some organic compounds such as ether, tetrahydrofuran, and p-dioxane can react with oxygen from the air forming unstable peroxides. Peroxide formation can occur under normal storage conditions, when compounds get concentrated due to evaporation, or when mixed with other compounds. These accumulated peroxides can violently explode when exposed to shock, friction, or heat.


React with water or moisture in the air releasing heat or flammable, toxic gas. Examples include alkali metals, alkaline earth metals, carbides, hydrides, inorganic chlorides, nitrides, peroxides, and phosphides.


They ignite spontaneously in air below 130oF (54oC). Often the flame is invisible. Examples of pyrophoric materials include silane, silicon tetrachloride, white and yellow phosphorus, sodium, tetraethyl lead, potassium, nickel carbonyl, and cesium.

Compressed gas:

A compressed gas is any material contained under pressure which is dissolved or liquefied by compression or refrigeration. They are potential explosives and projectiles and prudent safety practices should be followed when handling compressed gases since they expose users to both chemical and physical hazards.

5.0 Procedure:

5.1 General Laboratory Safety: All personnel working in the laboratory SHOULD:-

5.1.1. Always wear personal protective equipment (PPE) such as safety goggles, hand gloves, nose mask etc as required when performing hazardous test or handling corrosive chemicals. This includes eye protection, lab coat, gloves, and appropriate foot protection (no sandals). Gloves should be made of a material known to be resistant to permeation by the chemical in use.

5.1.2. Following masks are used for protection against dust/mist, gas vapors.

  • 3M 9004IN folded dust/mist respirator for protection against fine dust/mist.
  • 3M 8810 Dust/mist respirator FFP2 for protection against dusts and water based mists.
  • Venus V-7500-A1 gas filters for usage against certain organic gases & vapors e.g. carbon tetrachloride. Appropriate mask should be used based on the activity & degree of protection required.

5.1.3. Keep floors and work platforms clean, free from oil, water and other materials and mop the floor daily.

5.1.4. Hands should be thoroughly washed before entering and exiting the laboratory.

5.1.5. Do not interrupt others at work since distraction of attention is a common cause of Accidents

5.1.6. Know the potential hazards of the materials used in the laboratory. Review the Material Safety Data Sheet (MSDS) and container label prior to using a chemical.

5.1.7. Know the location of safety equipment such as emergency shower, eyewash, fire extinguishers, fire alarms, spill kits, first aid kits, and telephones.

5.1.8. Review emergency procedures to ensure that necessary supplies and equipment for spill response and other accidents are available.

5.1.9. Practice good housekeeping to minimize unsafe work conditions such as obstructed exits and safety equipment and accumulated chemical waste.

5.1.10. Wash skin promptly if contacted by any chemical, regardless of corrosiveness or toxicity.

5.1.11. Use break-resistant bottle carriers when transporting chemicals in glass containers that are greater than 500 ml.

5.1.12. Use fume hoods when processes or experiments may result in the release of toxic or flammable vapors, fumes or dusts.

5.2 All personnel working in the laboratory SHOULD NOT:-

5.2.1. Eat, drink, chew gum, or apply cosmetics in areas where chemicals are used and stored.

5.2.2. Store food in laboratory refrigerators, ice chests, cold rooms, or ovens.

5.2.3. Drink water from laboratory water sources.

5.2.4. Use laboratory glassware to prepare or consume food.

5.2.5. Smell or taste chemicals.

5.2.6. Pipette solutions by mouth.

5.2.7. Work alone in the laboratory without prior approval from the lab supervisor.

5.2.8. Leave potentially hazardous experiments or operations unattended without prior approval from the lab supervisor. In such instances, the lights in the laboratory should be left on and emergency phone numbers posted at the laboratory entrance.

5.3. General instruction for labeling & Storage Chemicals & Reagents:

5.3.1. Manufacturer’s chemical labels should never be removed or defaced until the chemical is completely used.

5.3.2. All chemical and waste containers should be clearly labeled with the full chemical name(s) [no use of abbreviation or formula] and appropriate hazard warning information. Unattended beakers, flasks, and other laboratory equipment containing chemicals used during an experiment should be labeled properly.

5.3.3. All hazardous waste containers must be labeled with the words “hazardous waste.”

5.3.4. Waste containers should NOT be filled to more than 90% of their capacity. All full waste containers should be disposed of promptly.

5.3.5. All chemical storage areas such as cabinets, shelves and refrigerator should be labeled to identify the hazardous nature of the chemicals stored within the area (e.g. flammable, corrosive, oxidizing agent, water reactive, toxins, carcinogens, and reproductive toxins). All signs should be legible and conspicuously placed.

5.4 Storage: The storage procedures listed below are not intended to be all-inclusive but should serve instead, to supplement more specific procedures and recommendations obtained from container labels, Material Safety Data Sheets (MSDS), and other chemical reference materials.

5.4.1. Inappropriate storage of incompatible or unknown chemicals can lead to spontaneous fire and explosions with the associated release of toxic gases. Hence, The solid and liquid chemicals & reagents are kept separately in their appropriate designated locations in QC store room.  Acids are kept separately on the bottom shelves. Liquid chemicals should not be stored above dry chemicals unless they are stored in secondary containers.

5.4.2. Refer attachment 1for compatibility table while storing the chemicals.

5.4.3. Do not keep large bottles of acids and other corrosive solvents above waist level.

5.4.4. A definite storage place should be provided for each chemical and the chemical should be returned to that location after each use.

5.4.5. Chemical containers should be in good condition before they are stored. Containers should be managed to prevent leaks.

5.4.6. Some Chemicals when stored together can be incompatible with each other and therefore it is important to review the chemical label and MSDS to determine the specific storage requirements and possible incompatibilities. Special attention should be given to the storage of chemicals that can be classified into two or more hazard groups. For example, acetic acid and acetic anhydride are both corrosive and flammable. In addition, perchloric acid is both corrosive and a strong oxidizing agent.

5.4.7. Incompatible Chemicals should be separated by distance. Physical barriers such as storage cabinets and secondary containers should be used to avoid contact of incompatible chemicals in the event that they are accidentally released or spilled.

5.4.8. Stored chemicals should not be exposed to heat or direct sunlight.

5.4.9. Liquid chemicals should be stored below eye level to avoid accidental spills.

5.4.10 Chemicals should not be stored in areas where they can be accidentally broken and spilled such as on the floor or on the edge of a bench top.

5.4.11 Chemicals should not be stored in areas where they obstruct aisles, exits, and emergency equipment.

5.5 Specific Instruction related to storage of different categories of chemicals         

5.5.1 Storage of corrosive chemicals:

  • Containers and equipment used for storage and processing of corrosive material should be resistant to corrosion. Corrosive chemicals should be stored below eye level, preferably near the floor to minimize the danger of their falling from cabinets or shelves.
  • Acids and caustics should be stored separately from each other. Secondary containers can be used to help with separation within a corrosive cabinet.
  • Inorganic acids should be separated from organic acids and flammable/combustible material (inorganic acids are particularly reactive with flammable/combustible material).
  • Acids should be segregated from active metals (e.g., sodium, potassium, and magnesium) and from chemicals which can generate toxic gases (e.g., sodium cyanide and iron sulfide).

5.5.2: Storage of flammable chemicals

  • Flammable / combustible liquid stored outside of flammable storage cabinets in the laboratory should be kept to the minimum necessary for the work being done.
  • Containers larger than 5 gallons (19 L) shall not be stored in the laboratory.
  • Flammable / combustible liquid stored in glass containers shall not exceed 1 gallon (3.8 L). Flammable / combustible liquids should only be stored in explosion-proof or laboratory-safe refrigeration equipment.
  • Flammable / combustible liquid containers filled or empty should not be stored in hallways or obstructing exits. Flammables and combustibles should not be stored near oxidizing, corrosives, or combustible material, near heat sources. Make sure all chemicals stored near flammable and combustibles are compatible.

5.5.3: Storage of carcinogenic chemicals:

These materials should be stored in areas designated for “particularly hazardous substances.” Storage areas should be clearly marked with the appropriate hazard warning signs. All containers of these materials (even if the material is in very small quantities such as 0.1%) should be clearly labeled with the chemical name or mixture components and the appropriate hazard warning information. Chemical storage areas should be secure to avoid spills or broken containers. Storage areas or laboratory rooms should be locked when laboratory personnel are not present.

5.5.4: Storage of oxidizing chemicals:

Oxidizing chemicals should be stored in a cool, dry place. Oxidizing chemicals should be segregated from organic material, flammables, combustibles and strong reducing agents such as zinc, alkaline metals, and formic acid. Oxidizing acids such as perchloric acid and nitric acid should be stored separately in compatible secondary containers away from other acids.

5.6: Storage of reactive Chemicals

5.6.1 Storage of explosive

  • Explosives should be kept to the minimum necessary for the procedure.
  • If there is a chance of explosion, use protective barriers (e.g., fume hood sash
  • And safety shield) or other method for isolating the material or process.
  • Explosives should be stored in a cool, dry, and protected area. Segregate from
  • Other material that could create a serious risk to life or property should an accident occur.

5.6.2      Storage of organic peroxides

  • Containers should be airtight and stored in a cool, dry place away from direct Sunlight. Segregate from incompatible chemicals.
  • Peroxide formers, liquid peroxides, or solutions should not be refrigerated below
  • the temperature at which the peroxide freezes or precipitates. Peroxides in these forms are extra sensitive to shock (never store diethyl ether in a refrigerator or freezer).
  • Unused peroxides should never be returned to the stock container.

5.6.3 Storage of water reactive

  • Water-reactive should be stored under mineral oil in a cool, dry place, isolated from other chemicals.
  • Water-reactive should not be stored near water, alcohols, and other compounds containing acidic OH.
  • In case of fire, keep water away. Appropriate fire extinguishers should be available in areas where water-reactives are stored & used (use Type “D” fire extinguisher to extinguish active metal fires).

5.6.4 Storage of pyrophorics.:

  • Pyrophorics should be used and stored in inert environments.
  • Appropriate fire extinguishers should be available in areas where pyrophorics are       Used

5.7 Instruction related to Safe Handling of different types of chemicals 

5.7.1  Handling of Corrosive Chemicals: 

Appropriate protective gloves which are resistant to permeation or penetration from corrosive chemicals should be selected and tested for the absence of pin holes prior to use. Eye wash and safety showers should be readily available in areas where corrosive chemicals are used and stored. In the event of skin and eye contact with a corrosive chemical, the affected area should be immediately flushed with copious amount of water for atleast 15 minutes. Contaminated clothing should be removed and medical attention sought. Corrosive chemicals should be handled in a fume hood to ensure that any possible hazardous or noxious fumes generated are adequately vented.When mixing concentrated acids with water, add the acid slowly to the water. Allow the acid to run down the side of a container and mix slowly to avoid violent reactions and splattering. Never add water to acid. Appropriate spill kit should be available in areas where corrosive chemicals are used and stored. Protective carriers should be used when transporting corrosive chemicals.

5.7.2 Handling flammable and combustible chemicals:

Appropriate personal protective equipment (gloves, lab coat, and safety goggles) should be worn when working with flammable / combustible liquids.Flammable / combustible liquids should never be heated using open flames. Preferred heat sources include steam baths, water baths, oil baths, hot air baths, and heating mantels.Ignition sources should be eliminated in areas where flammable vapors may be present. Flammable / combustible liquids should only be dispensed under a fume hood. Ventilation is one of the most effective ways to prevent the formation and concentration of flammable vapors. Appropriate fire extinguishers should be available in areas where flammables are used. 

5.7.3 Handling of carcinogens, toxins

Designated areas (e.g., fume hoods, glove boxes, lab benches, outside rooms, etc.) for material use should be established and the areas identified by signs or postings. Containment devices such as fume hoods (if necessary) and personal protective equipment (gloves, lab coat, and eye protection) should be used when handling these hazardous substances. Procedures for the safe use of the material and waste removal should be established prior to use. Decontamination procedures should be developed in advance and strictly followed. Only laboratory personnel trained to work with these substances should perform the work, and always within the designated area. Prior approval is required by the principal investigator or supervisor Only the minimum quantity of the material should be used.

5.7.4 Handling  of oxidizing chemicals:

Appropriate personal protective equipment (safety goggles, gloves, lab coat, etc.) should be worn when working with oxidizing chemicals. If a reaction is potentially explosive, or if the reaction is unknown, use a fume hood (with the sash down as a protective barrier), safety shield, or other methods for isolating the material or the process. Oxidizing chemicals can react violently when in contact with incompatible materials. For this reason, know the reactivity of the material involved in an experimental process. Assure that no extraneous material is in the area where it can become involved in a reaction. The quantity of oxidizing chemical used should be the minimum necessary for the procedure. Do not leave excessive amounts of an oxidizing chemical in the vicinity of the process. Perchloric acid must not be used in a regular chemical fume hood. A specially designed Perchloric Acid Fume Hood must be utilized for this purpose. 

5.7.3 Handling of Reactive chemicals

  • Explosives: Appropriate personal protective equipment (face shield, safety goggles, leather outer gloves, chemical resistant gloves, lab coat, etc.) should be worn when working with explosives. Before working with explosives, understand their chemical properties, know the products of side reactions, the incompatibility of certain chemicals, and monitor environmental catalysts such as temperature changes. Containers should be dated upon receipt and when opened. Expired explosives should be discarded promptly. 
  • Organic peroxides: Metal spatulas should not be used with peroxide formers. Only ceramic or plastic spatulas should be used. Contamination by metal can cause explosive decomposition. Friction, grinding, and all forms of impact, especially with solid organic peroxides should be avoided. Never use glass containers with screw cap lids or glass stoppers. Instead, use plastic bottles and sealers. Testing for the presence of peroxides should be performed periodically. Containers with obvious crystal formation around the lid or viscous liquid at the bottom of the container should NOT be opened or moved. 
  • Water-reactives & pyrophorics: Appropriate personal protective equipment (safety goggles, gloves, lab coat, etc.) should be worn when working with. 

5.8. Handling Chemical spillages:

Despite the best effort of researchers to practice safe science in the laboratory, accidents resulting in the release of chemicals will occur. For this reason, it is essential that laboratory personnel have a spill response plan which includes appropriate procedures and materials to adequately contain and cleanup a spill. The following procedures should be used as a guide to help laboratory personnel design an effective spill control plan for their laboratory 

5.8.1 Spill Response – Major Spill: In the event of a spill which:

  • involves the release of a type or quantity of chemical which poses an immediate risk to health;
  • involves an uncontrolled fire or explosion; or
  • involves serious personal injury; follow the steps outlined in the respective MSDS.

5.8.2 Spill Response – Minor Spill: In the event of a spill involving the release of a type or quantity of chemical which does not pose an immediate risk to health:

  • Notify other laboratory personnel of the accident.
  • Isolate the area. Close laboratory doors and evacuate the immediate area if necessary.
  • Remove all ignition sources and establish exhaust ventilation. Vent vapors to outside of building only (open windows and turn on fume hood).
  • Choose appropriate personal protective equipment (goggles, face shield, impervious gloves, lab coat, or apron, boots, respirator, etc.) (All laboratory personnel must be properly fit tested before using a respirator).
  • Confine and contain the spill. Cover with appropriate absorbent material. Sweep solid material into a dust pan and place in a sealed plastic container. Decontaminate the area with soap and water after cleanup and place residue in a plastic bag or another sealed plastic container. Bring the containers to waste disposal collection centre.

5.9 Handling & storage of compressed gases

5.9.1 Handling of Compressed gases

  • Safety glasses with side shields (or safety goggles) and other appropriate personal protective equipment should be worn when working with compressed gases.
  • Cylinders should be marked with a label that clearly identifies the contents.
  • All cylinders should be checked for damage prior to use. Do not repair damaged cylinders or valves. Damaged or defective cylinders, valves, etc., should be taken out of use immediately and returned to the manufacturer / distributor for repair.
  • A pressure-regulating device shall be used at all times to control the flow of gas from the cylinder.
  • The main cylinder valve shall be the only means by which gas flow is to be shut off. The correct position for the main valve is all the way on or all the way off.
  • Cylinder valves should never be lubricated, modified, forced, or tampered.
  • After connecting a cylinder, check for leaks at connections. Periodically check for leaks while the cylinder is in use.
  • Regulators and valves should be tightened firmly with the proper size wrench. Do not use adjustable wrenches or pliers because they may damage the nuts.
  • Cylinders should not be placed near heat or where they can become part of an electrical circuit.
  • Cylinders should not be exposed to temperatures above 50 °C (122 °F).
  • Rapid release of a compressed gas should be avoided because it will cause an unsecured gas hose to whip dangerously and also may build up enough static charge to ignite a flammable gas.
  • Appropriate regulators should be used on each gas cylinder. Threads and the configuration of valve outlets are different for each family of gases to avoid improper use. Adaptors and homemade modifications are prohibited.
  • Cylinders should never be bled completely empty. Leave a slight pressure to keep contaminants out.

5.9.2 Storage of compressed gas cylinders: 

  • When not in use cylinders should be stored with their main valve closed.
  • Cylinders must be stored upright and not on their side. All cylinders should be secured.
  • Cylinders awaiting use should be stored according to their hazard classes.
  • Cylinders should not be located where objects may strike or fall on them.
  • Cylinders should not be stored in damp areas or near salt, corrosive chemicals, chemical vapors, heat, or direct sunlight. Cylinders stored outside should be protected from the weather.

 6.0 Acceptance Criteria:

Not Applicable

7.0 Frequency:

As and when require during the quality control operations

8.0 Format for recording: 

Not applicable

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