CHEMICAL SAFETY MANUAL FOR THE ELECTROPLATING PLANT
1.0 Purpose
The purpose and the scope of this document is to provide all employees working in the
electroplating plant, with a company’s approved set of guidelines, procedures and best
practices for the safe reception, storage, transportation, use/handling, and disposal of
hazardous chemicals.
“Hazardous chemicals” or “chemical” in this manual refers to an element, compound, or
mixture of elements or compounds that posses physical health hazard as defined by the
Occupational Safety and Health standards.
1.1 Objective
The objective of this Chemical Safety manual is to serve as the written Hazard
Communication Plan and Chemical Hygiene Plan for the electroplating plant. This document
will provide safety guidelines to those employees who work with or are exposed to hazardous
chemicals in the routine course of their job duties.
Major topics addressed include information on Material Safety Data Sheets (SDSs), container
labeling requirements, safe handling, use, storage and disposal of hazardous chemicals, and
employee training programs. Additionally, this manual provides classifications of hazardous
chemicals, mode of exposure and their potential health hazards on the body, emergency
response procedures, proper personal protective equipment (PPE), first aid, and employee
‘rights to understand’ applying the Global Harmonization System.
This Chemical Safety document is not intended to be an extensive or fully comprehensive
manual, but rather a guide for knowledgeable employees.
1.2 Responsibilities
This manual intends to address the issue of classifying the potential hazards of chemicals,
and communicating information concerning hazards (e.g.
development and implementation of employee training programs regarding hazards of
chemicals), protective measures and appropriate protective measures to employees (e.g.
lists of hazardous chemicals present and labeling of containers of chemicals in the
workplace), and to preempt any legislative or regulatory enactments of a state, or political
subdivision of a state, pertaining to this subject.
1.2.1 Electroplating technical engineers
Individuals with this capacity will follow all guidelines, policies and regulations
presented in this manual.
 Comply with, enforce all internal and external standards, policies, procedures,
and referenced material regarding the use, handling, containment and disposal of
all hazardous chemicals as outlined in this document.
 Provide timely request for any activity that introduces new hazards or hazardous
materials.
 Clearly inform top management when a new activity may introduce new hazards.
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Ensure technical and support staff are trained and aware of all hazards, safe
handling and disposal of hazardous chemicals.
Ensure appropriate PPE are supplied to all staff and ensure they are trained on
the appropriate use of PPE.
Ensure safety equipment are available at the plant and used when necessary.
Complete necessary documentation to report potential over exposures and injuries
1.2.2 Electroplating process engineers
 Compile and maintain workplace chemical list.
 Regularly remind support staff regarding the hazards associated with the chemicals in
use, safe handling and appropriate disposal procedures.
 Always ensure the availability of documents or electronic database of MSDS at the
site.
 Conduct routine plant chemical safety evaluations.
 Comply with and adhere to all standards, policies, procedures and referenced material
regarding the use, handling, containment and disposal of all hazardous chemicals as
outlined in this document.
 Clearly inform technical engineer when a new activity or operating conditions may
introduce new hazards in the process.
 Ensure appropriate PPEs are available at the plant and are easily accessible before
production process.
 Ensuring safety equipment are available in the plant and used when necessary.
 Complete necessary documentation to report potential over exposures and injuries.
1.3 chemical safety plan
The Occupational Safety and Health Administration (OSHA) regulation "Occupational
Exposure to Hazardous Chemicals” mandates the development of a Chemical Safety
Plan which is capable of protecting employees from health hazards associated with
hazardous chemicals in the laboratory and other processing plants, and are capable of
keeping exposures below OSHA Permissible Exposure Limits. Thus, this Chemical
Safety Plan is developed in context of the Environment, Health, and Safety (EHS)
regulations. This section is designed to supplement galvanization section and laboratory
specific safety manuals and procedures that already addressed chemical safety, and
contains the following elements:
1.3.1 Standard Operating Procedures
There will be a well-written set of instructions describing the systematic procedures that will
be undertaken to ensure safe use, handling, containment and disposal of all hazardous
chemicals. This will clearly explains the steps taken to complete a task and informs the
employee of any risks associated with the process.
1.3.2 Control Measures
The exposure to hazardous chemicals in the plant shall majorly be controlled by engineering
controls, personal protective equipment, and other general control measures.
Engineering controls: There are varieties of engineering controls that will be used in the
plant to control exposures to hazardous chemicals. Some of the engineering controls that will
be used may include dilution ventilation, local exhaust ventilation (fume hoods), and proper
storage facilities.
Personal protective equipment: Personal protective equipment (PPE) will be available to
plant staff for use to reduce exposures to hazardous chemicals during routine operations.
Common PPE such as goggles, gloves, safety boots, face shields, respirators and aprons will
be required for use with hazardous chemicals.
Other control methods that will be used to determine and reduce employee exposures to
hazardous chemicals in the plant may include exposure monitoring, testing eyewash and
emergency shower facilities, developing emergency procedures, proper container selection,
and substitution of less toxic chemicals whenever possible.
1.3.3 Employees Training
Both internal and external chemical safety trainings will be conducted from time to time in
accordance with the company’s programs and policies.
1.3.4 First Aids and Medical Examinations
First Aids and medical examinations will be made available to the plant workers who shall be
exposed to the hazardous chemicals. All work related medical examinations and consultations
will be performed by or under the direct supervision of a licensed physician and will be
provided in accordance with the company policies.
Other chemical safety plan will require the use of additional provisions such as:
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Establishment of a safe designated area in case of an emergency spills and exposure.
Procedures for safe removal of contaminated waste.
Decontamination procedures.
2.0 Classification of chemicals used at electroplating plant
The purpose of this section is to provide information to electroplating staff regarding major
potential hazards of the various classes of chemicals that will be used in the process.
Here, process chemicals are classified into various hazard classes in accordance with their
physiochemical properties and health hazards as carcinogenic, highly toxic, or acutely
hazardous as summarized in the table 1.
Table 1. Classes of electroplating chemicals
Class
Corrosive and
carcinogenic
acids
Examples
 Sulphuric acid
 Hydrochloric acid
 Chromic acid
 Nitric acid
 Boric acid
Corrosive and
carcinogenic
alkalis/ bases
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Sodium hydroxide
Potassium
hydroxide
Corrosive acid
salts
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Ammonium nitrate
Ammonium
chloride
Ammonium
sulphate
Zinc
monophosphate
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Sodium cyanide
Copper cyanide
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Highly toxic and
poisonous
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Potential hazards
 Can severely irritate and burn
the skin and eyes, and may
lead to blindness.
 Inhalation can irritate the
nose, throat and the lungs.
 Higher exposures can causes
headache, nausea and buildup
of fluids in the lungs.
 Repeated exposure can cause
permanent lung damage,
damage to teeth and upset
stomach.
 Eye contact can result into
corneal damage or blindness.
 Skin contact can produce
inflammation and blistering.
 Inhalation causes irritation to
gastro-intestinal or
respiratory track
characterized by burning,
sneezing and coughing.
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Contact with skin causes
burns
Contacts with eyes, nose,
throat, and lungs causes
irritation
High level of exposure
causes fatigue, headache and
blue color to the skin and lips
Contacts can irritate eyes,
nose, skin and throat.
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Chromic anhydride
Sodium trisilicate
Sodium silicon
flouride
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flammable
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Gasoline
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High exposure causes
poisoning with headache,
weakness, confusion and
pounding of the heart, coma
and even death.
Repeated exposure causes
nosebleeds and sores in the
nose, and/ or enlargement of
the thyroid gland.
Contact can irritate and burn
the skin and eyes with
possible eye damage.
Inhalation can irritate the
nose, lungs
High and repeated exposure
can cause headache,
dizziness, drying and
cracking of the skin with
redness.
Exposure near the ignition
sources can cause fire.
2.1 Heavy metals and their compounds
Heavy metals are relatively harmless in the metallic state, but their fumes, dust, and soluble
compounds are well-known toxins. Some are carcinogenic while others are nephrotoxins,
hepatotoxins, or neurotoxins. Here, the most common heavy metals that shall be dealt with in
the electroplating process include cadmium, chromium, lead, nickel, copper, Aluminum and,
Zinc. Acute toxic effects from exposure to heavy metals will result from inhalation and
ingestion of dusts or inhalation of their fumes during the plating process.
Metal fumes are generally more hazardous than dusts because the particles in fumes can enter
the bloodstream easier, with cadmium being one of the most toxic metals when inhaled.
Bronchitis, chemical pneumonia, and pulmonary edema may result when these metals are
inhaled with major symptoms including nausea, vomiting, abdominal pain, and diarrhea.
Chronic exposure to heavy metals may lead to long-term effects such as damage to the
nervous system, brain, liver and kidneys.
3.0 Emergency chemical Response plan
Unexpected accidents and inadvertent exposures may occur when working with hazardous
chemicals. Being prepared to respond swiftly and efficiently will be the best way to keep the
electroplating personnel safe, minimize damage to equipment and facilities, and prevent
environmental releases.
3.1 Hazardous Chemical Exposure
One of the most common incidents involving hazardous chemicals is unintended exposure.
Exposure can occur when a chemical is spilled onto skin, is splashed into eyes, mucus
membranes, or onto clothing, or is inadvertently ingested or
inhaled. The following procedures must be reviewed before handling hazardous chemicals in
the plant and should be used as a reference if exposure occurs.
When exposed to a hazardous chemical, seeking assistance from other personnel is an
important first step. The assisting personnel can acquire first aid and spill kits, assist in using
safety equipment, help apply first aid, and contact emergency responders.
3.1.1 Skin exposure;
 If the skin is exposed to hazardous chemicals, immediately flush the affected area
with flowing water for not less than 15 minutes and remove any clothing as necessary
to facilitate clearing any residual materials.
 Check the chemical's SDS to determine if special procedures are needed or if any
delayed effects should be expected.
 Report the incident to your supervisor immediately and seek medical attention for
even minor chemical burns.
 Do not use creams, lotions, or salves on exposed areas unless applied under the
direction of a licensed health personnel
3.1.2 Liquid or Powder Exposure to the Eyes or Mucus Membrane;
 Immediately flush with water from an available emergency drench hose or eyewash
station for not less than 15 minutes.
 Hold the affected individual’s eyelids open, and instruct him or her to move the eye
up and down and sideways to wash thoroughly behind the eye and seek immediate
medical attention.
 Bring a copy of the SDS for the exposing chemical and provide this document to the
treating medical personnel.
3.1.3 Clothing or Large Skin Exposure;
 Immediately place the victim underneath the nearest safety shower and activate the
shower.
 With the water flowing quickly, remove and if necessary cut off all contaminated
clothing, shoes, and jewelry. Do not limit the showering of body areas because of
modesty.
 When removing clothing, take care not to contaminate unexposed skin or the eyes.
Keeping the eyes and mouth shut while under the shower will reduce
the potential for chemicals, vapors, or gases to affect the eyes or to be inhaled or
ingested.
 Provide the exposed person with a clean lab coat, scrubs, or clothing and if severely
burned, be careful when covering the injured skin.
 Seek immediate medical attention with a copy of the SDS for the exposing chemical
and provide this document to the treating medical personnel
 Report the incident to the immediate supervisor and management.
3.1.4 Chemical Spills;
If you come across a hazardous material spill during process operations, be able to identify
whether the spill is small or major.
If it is a small spill (less than 1 liter in volume or 1 kg for powdered materials), execute
the following control mitigation procedures:
 Inform the immediate supervisor and others in the area about the spill.
 Restrict further access to the area.
 Do not enter the spill area alone.
 Use proper personal protective equipment appropriate for the spill agent.
 Neutralize or secure the spill using the appropriate absorbent material available.
 Dispose of the spill-cleanup material as hazardous waste into the designated
area/container for waste disposal.
 Do not attempt to clean, disinfect, or absorb spill materials without proper emergency
response training and equipment.
 If you are injured, seek immediate first aid services and medical attention.
In case of a major spill (greater than 1 liter in volume or 1 kg of powdered material),
personnel should follow the following mitigation guidelines:
 Inform the immediate supervisor and others in the area about the spill..
 Restrict further access to the area in order to secure it.
 Do not attempt to clean, neutralize, or disinfect major spills alone awaiting emergency
response action from the technical emergency team.
 Remain outside the spill area to report to responders on the spill agent.
 If you are injured, seek immediate first aid services and medical attention.
3.2 Personal Hygiene, Habits, and Practices
Personal hygiene in the plant is directed mainly toward the prevention of occupationally
acquired disease or physical injury. However, it can raise the quality of work by reducing
possibilities for contamination of process bath compositions. Habitual adherence to good
hygiene and production practices shall provide a margin of safety in situations where the
hazard may be unrecognized. The following guidelines are standard operating procedures to
be followed by all staff under the electroplating plant.
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Food, candy, gum, beverages, and tobacco for human consumption shall not be stored or
consumed inside the plant facilities.
The source of drinking water shall be provided outside the production and storage
facilities.
Smoking is not permitted in the production or storage rooms.
Inappropriate use of PPEs shall not be permitted
The appropriate PPEs should be worn when transporting/carrying, and before starting any
operation involving hazardous chemicals.
All process chemical tanks should be inspected for leakages before starting any routine
operations
3.3 Emergency and safety trainings
Hazard Emergency and safety training is required for all staff in the electroplating plant. The
Safety Training shall be offered by the safety department of pro-heli international services
ltd, and the general training session shall cover topics related to the various categories of
hazardous chemicals present at the plant, interpretation of SDSs, safe handling, storage, and
disposal procedures for specific chemicals used in the electroplating process. Additionally,
training on use and maintenance of PPEs, emergency response procedures and first aid
treatment shall also be discussed.
4.0 Chemical handling
4.1 Chemical registration/ inventory
This will be done up on recipient of new consignment/batch of process chemicals and a
registration process shall ensure extraction of the following information:
Chemical name and class, CAS number, receipt date, production and expiry date, storage
location, container type and size, quantity, unit of measure and chemical hazard. This
information will be contained in the chemical inventory form as in the appendix III
4.1.1 Material Safety Data Sheet
Material Safety Data Sheets (MSDSs) are documents containing hazard and safe handling
information that is prepared in accordance with the requirements of the Hazard
Communication Standard. It describes the properties and uses of chemical product or
formulation including identity, chemical and physical properties, human hazard information,
precaution for use and safe handling information. The Hazard Communication Standard
(HCS), revised in 2012, requires that the chemical manufacturer, distributor, or importer
provide Safety Data Sheets (SDSs) for each hazardous chemical to downstream users to
communicate information on safe handling and use of these chemicals.
All MSDSs should at least contain the following safety information:
• Identification
• Hazard(s) Identification
• Composition/Information on Ingredients
• First-Aid Measures
• Fire-Fighting Measures
• Accidental Release Measures
• Handling and Storage
• Exposure Controls/Personal Protection
• Physical and Chemical Properties
• Stability and Reactivity
• Toxilogical Information
• Ecological Information (non-mandatory)
• Disposal Considerations (non-mandatory)
• Transport Information (non-mandatory)
• Regulatory Information (non-mandatory)
• Other Information
4.2 Chemical transportation
This section presents safe procedures to electroplating staff for the movement of chemical
materials in compliance to all applicable regulations. It outlines standard operating
procedures to be observed when transporting these chemicals to their required points of
application during production process or within the storage facilities. These include the
following:
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When transporting chemicals from storage and within production facilities, a secondary
container must be used to hold the original container at all times. Acceptable secondary
containers will be able to contain all of the materials in the event of a spill or breakage of
the original container. Thus, when transporting chemicals from storeroom to the
production facility, individuals will not be permitted to take these materials without a
secondary container.
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Hazardous chemicals must never be left unattended in public spaces during
transportation. Individuals transporting chemicals
through public spaces must be familiar with the material’s hazards and know what to do
in case of a spill or fumes.
Whenever transporting hazardous chemicals in bulk from storage facility to the
production room, always use trollies with side panels to avoid fall offs and spills. Do not
allow containers to collide with each other during transportation.
Wear appropriate personal protective equipment (PPE) when transporting chemicals.
Protective eyewear, foot wares, hand gloves and Aprons, etc., should be worn.
Use a hand-held rubber safety bottle carrier for transporting liquids and hazardous solids
in glass containers.
Incompatible chemicals must be kept separated during transportation.
Never pick up a bottle by the cap or lid.
Do not pick or transport extremely hazardous materials in bulk package by yourself.
Ensure that a spill kit is available when transporting hazardous liquids.
4.3 Storage and Segregation
Proper chemical storage within the plant facility will be an essential part of any chemical
safety program. Adhering to appropriate segregation of hazardous chemicals will lessen the
risk of fire, accidental mixing during emergencies, and ultimately minimize employee
exposure to hazardous chemicals. The following general storage and chemical segregation
requirements (Appendix II) will be mandatory for the electroplating plant facilities:
 All chemical components and mixtures should be accurately labeled.
 All new chemicals will be dated with the date received, date opened and the expiry
date.
 Flammable liquids will be stored in flammable liquid storage cabins. Where feasible,
these cabinets will be vented.
 Acids, bases and flammable materials will be stored separately so that in the event of
an accident, the violent chemical reactions that can occur when certain compounds in
these classes are mixed should not exacerbate the situation.
 All acids will be stored in an acid storage cabin and this should be vented.
 Acids and all corrosives will not be stored under sinks. Storage space underneath
sinks will be strictly meant for cleaning supplies.
 Strong oxidizers, such as sulphuric acid, will be stored away from organic materials
to reduce the risk of fire, and away from reducing agents to reduce the risk of violent
reactions.
 Cyanides and sulfides will be stored separately from acidic compounds. The
poisonous gases, hydrogen cyanide and hydrogen sulfide, are released when these
compounds react with acids.
 Hazardous liquid chemicals will not be stored above eye level to avoid spilling
liquids in the eye.
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Periodically inspect storage areas and note signs of leakage and corrosion, and make
arrangements to dispose of expired materials or those no longer needed in the
process.
4.3.1 General Operating Procedures for chemical inspection in storage facilities.
The chemical storage building shall be inspected once every week, and there will be a
well-designed general inspection sheet for all storage facilities.(appendix needed)
The inspection activity shall include looking for leaking bottles/containers, degrading
chemicals, labels falling off, cleanliness, blocked isles and any condition that may or will
pose a hazard.
No chemical shall be stored or placed in the corridors or hallways.
Fuming chemicals shall be checked to ensure they are not expired.
The inspection will also include all safety equipment such as fire extinguishers, spill kits,
alarm panel, and other fire suppression system.
Flashlights will be inspected once a month to ensure their operation.
The hazardous waste disposal areas must be inspected weekly or on a time frame in
accordance with environmental regulations.
The storage building will be cleaned at least once a month; this will include sweeping the
floors, emptying the trash receptacles and discarding any empty boxes and containers.
4.4 chemical dispensing.
In this section, dispensing shall refer to the act of preparing chemicals and distributing it to
the required points of application in the process with adequate information, and technical
knowledge required to carry out the process.
The dispensing of chemicals shall involves interpretation of the material requisition sheets
and the service requirements, MSDS, technical knowledge required to carry out the
instructions and delivers with accuracy and safety to the personnel and equipment/ instrument
being used.
There are considerable varieties of factors that require close attention in dispensing, and
proficiency requires the establishment of a routine system that can be followed safely.
The following shall be the general procedures for dispensing chemical materials during the
production process:
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The production department shall give Material Requisition sheet as per Batch
Manufacturing Record to Store department.
The chemical material shall be brought to the production facility upon release from
the store, and its MSDSs reviewed before use to prevent any potential hazard.
Dispensing shall be carried out in proper clean garments that do not shed lint and in a
fume hood dispensing room. Garments include head cap, mask, overcoat, factory
shoes and clean gloves.
Only materials bearing "APPROVED" labels on their containers shall be dispensed.
Materials shall be dispensed as per the quantities specified in Raw material requisition
form found in a duly signed BMR.
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All materials shall be dispensed on 'First Expiry First Out' (FEFO) and 'First In First
Out' (FIFO) basis using calibrated weighing balances and measuring cylinders.
Only clean containers/drums shall be used for holding dispensed materials and should
be kept closed after dispensing.
Only authorized persons shall carry out the dispensing process.
Powdered materials shall be dispensed in poly bags which shall be secured using a
cable tie and placed in plastic or fiber drums. Each drum/bag shall bear a
"DISPENSED" label, tied or fixed to it which shall include; name of material
dispensed, Tank/ Bath in which material is going to be used, Batch number of
product, Gross, Tare and net weights, person who issued, weighed and checked, date
of dispensing, Mfg and expiry date of the chemical material being dispensed.
Chemical materials that reacts exothermically with water (e.g. strong acids like
sulphuric acid, hydrochloric acid, nitric acid, etc.) shall be added to water during
dispensing, not water to acid.
One material at a time shall be dispensed using clean scoops and container shall be
sealed, covered and returned to its point of location in the store.
Adequate space shall be maintained in the dispensing room to avoid mix-ups, errors
and cross contamination.
Material requisition form shall be filled and signed after dispensing.
Dispensing Equipment
5.0 Hazardous Chemical Waste Disposal and Management
5.1 Responsibilities
The hazardous waste management program at pro-heli international services ltd is designed to
provide safe, effective and economical disposal of chemical waste generated by the different
production sections in compliance with the Environment, Health and Safety regulations. This
section lists down the responsibilities to be undertaken by the electroplating staff while
discharging hazardous chemical waste generated from the plant. The plant technical
engineers are responsible for overseeing the day-to-day operations of the hazardous waste
disposal program. This includes supervising staff, and enforcing safe disposal procedures in
the disposal facilities; conducting inspections of the chemical waste disposal areas; and
evaluating the methods used for hazardous waste management.
Process engineers are responsible for monitoring all waste disposal activities in the plant,
train and guide other support staff to ensure that hazardous materials are collected, discharged
and stored properly and that appropriate records are kept.
Process engineers are also responsible for enforcing proper collection and storage of the
wastes created in the plant, enforcing the necessary maintenance on systems vital to the safe
operation of the waste handling facilities.
The company security department shall provide security and ensure that access to the
hazardous waste facilities is controlled. They will also serve a central role in emergency
situations.
5.2 Chemical Waste treatment and disposal methods
5.2.1 Chemical neutralization and precipitation
While it is always desirable to employ a suitable technologies/approaches for safe disposal of
hazardous chemical waste, there may be situations where these required methods are not
available, practicable for other reasons (e.g., lack of infrastructure or inability to transport the
chemicals/wastes, etc.). Since many of the chemicals require some form of treatment (e.g.,
neutralization), before they can be safely disposed of to the environment, this section
provides a comprehensive compilation and practical details of specific methods for chemical
neutralization and treatment, which shall be applicable to individual chemicals, or groups of
chemicals used to make the electroplating bath composition at Pro-Heli international services
ltd.
In general, the contaminants contained in the electroplating wastewater that are toxic in
nature and require treatment are corrosive acids and bases, cyanide, hexavalent chromium
and heavy metals.
Several types of treatment methods have been developed for each specific contaminant. Each
treatment method has its particular application and constraints.
Table 2 summarizes the most common methods of treatment of these types of contaminants.
Table 2. Methods of treatment of electroplating wastes
Parameter
Treatment of corrosive acids and bases
Treatment of cyanide
Treatment of hexavalent chromium
Treatment of metals
Type of treatment method
Neutralization
Chlorination
Ozonation
Electrolysis
Ion exchange
Reduction to trivalent chromium and
precipitation
Cementation
Precipitation as barium salt
Ion exchange
Neutralization and Precipitation as
hydroxides (for non-complexed metal)
Precipitation as metal sulphide (for
both complexed and non-complexed
metal)
Destruction of complexes and
precipitation (for complexed metal)
Ion exchange
5.2.1.1 Treatment of electroplating spent wash containing inorganic acids.
This method will be used for safe disposal of the electroplating bath composition having
inorganic acids such as sulphuric acid, hydrochloric acid, and nitric acid. Thus, the
electroplating bath solutions from Tanks 1.13, 2.4, 2.12, or generally, where the solution is
acidic with PH value ≤5.0, this method shall be applied.
The following safe procedures for neutralization shall be followed:
 The hazardous bath solutions shall be drained and taken into a large corrosion
resistance plastic drum, and the initial pH shall be determined.
 The acidic effluent shall then be diluted with soft water at a ratio of approximately
1:10 prior to neutralization.
 The basic materials, such as sodium bicarbonate, potassium bicarbonate, calcium
bicarbonate, limestone shall be selected and used for neutralization.
 Slowly add the solution of the basic material selected above to the diluted effluent.
(Always check pH.).
 Continue the process until a pH between 6 and 8 is obtained.
 Dilute the solution further, approximately 1 to 10parts water.
 Dispose of the neutralized effluent in the sewer system with 1to 18parts water or, mix
with dry sand and burry it in a sanitary landfill.
Treatment of an Alkaline/Basic electroplating spent wash
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The basic effluent shall be diluted with soft water at a ratio of approximately 1:10
prior to neutralization in a large corrosion resistant container, after determining
the initial pH. Soft water shall be slowly added to the basic effluent.
 Select a strong acidic material (e.g., hydrochloric acid, sulphuric acid). This must
be diluted at an approximate ratio of 1:10 or greater prior to utilization.
 Slowly add dilute base to a solution of the acidic material selected above. (Always
check pH.)
 Continue the process until a pH of between 6 and 8 is obtained.
 Dilute the solution further, approximately 1 to 10, with water.
 Dispose of the neutralized effluent in the sewer system with 1 to 18parts water or,
mix with dry sand and burry it in a sanitary landfill.
This method can be suitable for chemical effluents from Tanks: 2.1, 2.6, 3.1, 3.5, and
other basic effluents with pH value ≥8.5.
Note: In the event where the drained effluents from methods 1 and 2 are available, both
can be diluted separately and then later used to neutralize the other for safe disposal.
However, this may need some laboratory study and practical trials for its impeccable
application before implementing it on industrial, since it is just a suggestion.
5.2.1.1 Treatment of electroplating spent wash containing Inorganic Salts
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Drain the salty effluent and dilute it with large excess of soft water to an
approximate ratio of 1:10.
Add excess of soda ash, sodium (calcium) carbonate, and let stand 24 hours.
Remove aqueous layer, check the pH and neutralize with acid or basic material, if
necessary, to pH 6-8.
Dispose of the liquid layer in sewer with a large excess of water.
The sludge shall be disposed of in a landfill by further mixing with dry sand, in
accordance with environmental regulations.
5.2.1.2 Treatment of Cyanide Waste
a) Chlorination.
The use of sodium hypochlorite to oxidize the cyanide to less toxic products is the most
widely practiced treatment method and is considered most suitable to small electroplating
plants.
The destruction of cyanide by sodium hypochlorite is accomplished in the following stages:
1st stage:
(a) NaCN+NaOCl+H2O
CNCl+2NaOH
(b) CNC1+2NaOH
NaCNO+NaCl+H20
2nd stage:
2NaCNO +2NaOH+3NaOCl
2Na2C03,+3NaCl+N2+H20
Overall:
2NaCN +5NaOCI+2NaOH
2Na2C0,+3NaCl+N2+H20
The rate of destruction of cyanide is pH dependent and may be affected by the presence of
metals.
This shall be effected through the following procedures;
Where metal removal is not required
 The hazardous cyanide solution shall be placed in a large corrosion resistant container
and made neutral with sodium hypochlorite solution to a pH of about 6-8.
 Add an excess of ferrous sulphate solution.
 Dilute the solution further, approximately 1 to 10, with water.
 After approx. 1-2 hrs, dispose of with an excess of water in sewer system or, mix with
dry sand and burry it in a sanitary landfill.
Where metal removal is required.
Cyanide treatment shall consist of two reaction tanks.
In the first tank, conditions are adjusted to oxidize cyanides to cyanates by the introduction of
chlorine and caustic to maintain a pH range of 9.5 to 10.0. Chlorine is typically added as
chlorine gas or sodium hypochlorite.
In the second reaction tank, conditions are maintained to oxidize cyanate to carbon dioxide
and nitrogen.
Additional chlorine is added and adequate caustic is mixed in to maintain a pH of 8.0.
An additional tank may be added for holding and treatment to meet discharge limitations.
Detention times of 45 minutes for each reaction tank is sufficient.
b) Electrolytic oxidation.
Oxidation by anodic oxidation is particularly suitable for high concentrations.
Removal rate can be as high as 260-380 mg/Ah for cyanide concentrations between 10003000 mg/l, but rapidly decreases at lower concentrations.
Electrolytic oxidation is mainly used to pre-treat highly concentrated cyanide waste from an
electroplating shop, where there is direct current power supply, to a lower concentration after
which conventional chlorination oxidation is used for complete treatment. The operating cost
for the destruction of cyanide by electrolysis at high concentration is only about 40-60% of
the cost of chemical treatment by chlorination.
c) Ion exchange
Cyanide in wastewater may be removed by adsorption on anionic exchange resins. The
adsorbed cyanide may later be eluted off by passing regenerants, such as sodium hydroxide
or sodium chloride, through the resins. The regenerated cyanide may be reused as process
chemicals or treated before discharge to the sewer system.
5.2.1.3 Treatment of Chromium solution
a) Reduction of hexavalent chromium and precipitation.
The most widely used method of treating hexavalent chromium is to reduce it chemically to a
trivalent state and subsequently precipitate it out of solution as hydroxides. The common
chemical reductants used by small electroplaters are sodium sulphite (Na2S03), sodium
bisulphite (NaHSO,), sodium metabisulphite (Na2S2O5) and ferrous sulphate (FeS04.7H20).
The reduction reactions are:
With sodium sulphate;
2H2CrO4+ 3Na2SO4 + 3H2SO4
Cr2(SO4)3 + 3Na2SO4 + 5H2O
With sodium bisulphite;
4H2CrO4 + 6NaHSO3 + 3H2SO4
2Cr2(SO4)3 + 3Na2SO4 + 10H2O
With sodium metabisulphite;
4H2CrO4 + 3Na2S2O5 + 3H2SO4
2Cr2(SO4)3 +3Na2SO4 +7H2O
With Ferrous sulphate;
2H2CrO4 +6FeSO4 + 6H2SO4
Cr2(SO4)3 + 3Fe2(SO4)3 + 8H2O
This method can practically be applied as follows:
 Drain and dilute the dichromate effluent with soft water to an approximate ratio of
1:10.
 Acidify with dilute sulphuric acid to a pH of 2.5 to 3.5.
 Slowly, and with stirring, add solid sodium sulphite (Na2S03), or sodium bisulphite
(NaHSO,), or sodium metabisulphite (Na2S2O5), or ferrous sulphate (FeS04.7H20)
until the solution becomes cloudy and blue colored.




Neutralize the solution with sodium carbonate. After a few minutes, a blue-grey
flocculent precipitate is formed.
Filter immediately through Celite, or let stand for a week, when much of the
supernatant can be decanted. The remaining liquid is then filtered off.
The liquid can be washed into sewer with large amount of water or mixed with dry
sand and buried in a sanitary landfill.
The solid residue should be washed with hot water to remove sodium sulphate, then
dried, packaged, labelled, and sent to a sanitary landfill.
c) Cementation
This is the use of scrap metals to electrochemically reduce the hexavalent chromium. By
allowing the electroplating waste containing hexavalent chromium to come into contact with
scraps of reactive metals (such as iron, Zinc or Aluminum), the hexavalent chromium is
reduced. Although the cementation reactions with zinc and iron have to be carried out under
acidic condition, the cementation reaction with Aluminum scrap under alkaline condition
have been tried with some degree of success. In this way, the reduction of hexavalent
chromium to trivalent state and the precipitation of trivalent chromium can be accomplished
in one-step. Thus, this treatment process requires less operator attention and reduces the need
for sophiscated control equipment.
In summary, the use of metal scraps for chromium treatment can lower the chemical costs
and simplify the treatment operation by eliminating the need for careful dosage of treatment
chemicals.
c) Ion exchange
ion exchange is one of the more widely employed chromium and chromic acid recovery
processes. Although cation exchange can be used to recover trivalent chromium, it is
seldomly practiced due to complexity of operation.
5.2.1.4 Treatment of Metals
a) Removal as hydroxides
Precipitation of metals contained in the electroplating waste is the most widely adopted
treatment method for removal of metals. Each metal species has a particular optimum pH
range for its maximum removal. Table 3 shows the recommended pH range for the removal
of some common metals as metal hydroxides.
The more commonly used chemicals for pH adjustment are caustic soda and lime, caustic
soda being the more expensive. However, it will contribute to a much smaller amount of
sludge generated when compared to the use of lime. Lime is cheaper to purchase but its
reaction rate is slower and a considerable excess will be required if encapsulation occurs.
Sedimentation of the resulting hydroxide sludge tends to be more rapid and may not require
the use of flocculants.
Table 3: recommended pH range for the removal of some common metals in the
electroplating spent wash as metal hydroxides
Common electroplating metals
Copper, Cu2+
Zinc, Zn2+
Nickel, Ni2+
Chromium, Cr3+
Recommended pH range
5.5-11.5
7.0-8.5
7.5-10.5
4.5-8.5
Cadmium, Cd2+
Lead, Pb2+
8.0-10.5
8.0-9.0
This metal removal process occurs by several unit operations, as displayed in the process
flow below. The process flow also shows the points in the treatment process where the pH
must be adjusted to insure adequate metals and metals solids removal. This process will be
summarized in the appendix
b) Removal as sulphide
Owing to the inherent solubility of metal hydroxides, it may not be possible to reduce the
metal contents to a very low concentration such as 0.1 mg/l by precipitation method as metal
hydroxides. Thus, in this case, it may be necessary to precipitate the metals as insoluble
sulphides. The principle of sulphide precipitation is that the solubilities of metal sulphides are
generally much lower than the hydroxides. The theoretical solubilities of metal hydroxides
and sulphides are shown in Table 4. Hence, by forming metal sulphides, the metal
concentrations in the electroplating spent wash can substantially be reduced to very low
levels.
The sulphide reagent may be added in form of soluble sodium sulphide or insoluble ferrous
sulphide.
This removal method, however, suffers from some operational difficulties such as less
settleable sludge and the need for control of addition of reaction chemicals.
Table 4: Theoretical solubilities of metal hydroxides and sulphides.
Metals
Solubility of metal ions(mg/l)
As hydroxide
As sulphide
2+
Zinc, Zn
1.1
2.3x10-7
Copper, Cu2+
2.2x10-2
5.8x10-18
Nickel, Ni2+
6.9x10-3
6.9x10-8
Chromium, Cr3+
8.4x10-4
No ppt
2+
-5
Cadmium, Cd
2.3x10
6.7x10-10
Iron, Fe3+
8.9x10-1
3.4x10-5
Tin, Sn2+
1.1x10-4
3.8x10-8
Lead, Pb2+
2.1
3.8x10-9
5.2.2 Engineered landfill
This is an official site, which has appropriate protective lining, and is approved for the
disposal of hazardous waste, as per applicable national regulations.
This method shall be suitable for Non-hazardous chemical solid waste, which will include
expired stock materials, and other waste from trash containers. The disposal procedure for the
expired chemicals will rely upon the following list of solid chemicals, which are not
considered hazardous and are therefore suitable for disposal with regular waste in a landfill.
A. Organic Chemicals:
Activated carbon
Sugars and sugar alcohols
Starch
Citric acid and its Na, K, Mg, Ca, NH4 salts
Lactic acid and its Na, K, Mg, Ca, NH4 salts
Urea
B. Inorganic Chemicals:
Silica
Sulphates: Na, K, Mg, Ca, Sr, NH4
Phosphates: Na, K, Mg, Ca, Sr, NH4
Carbonates: Na, K, Mg, Ca, Sr, NH4
Oxides: B, Mg, Ca, Sr, Al, Si, Ti, Mn, Fe, Co, Cu
Chlorides: Ca, Na, K, Mg, NH4
Borates: Na, K, Mg, Ca
5.2.3 External disposal and treatment
For the purposes of this document, the term ‘External disposal and treatment
’ refers to all-inclusive options, i.e., companies like Luwero Industries Limited that will be
called to the location where chemical waste are stored in sealed containers, and will take care
of all necessary steps from the safe handling, transport and storage, if required, to the
treatment and disposal of the chemicals.
5.2.4 Safe disposal of Empty Hazardous Chemical Containers
Containers that are empty and have not more than 2.5 cm of chemical residue remaining on
the bottom can be triple rinsed.
The original label must be marked out and placed outside the production room for disposal by
the support staff.
Empty containers of acutely hazardous chemicals must be triple rinsed with an appropriate
solvent or water prior to disposal.
The waste solvent must be disposed of as hazardous waste.
5.2.4.1 Selection of Waste Containers, Packaging and Labeling
 In selecting a waste container, the compatibility of the waste with the container shall
be the primary concern.
 Unbreakable containers should be used whenever feasible.
 Polyethylene cans/ drums are best because of their high resistance to many types of
chemicals and shall be used for chemical waste storage where necessary.
 These containers shall be filled not more than 2/3 full for easier transfer.
 Continued re-use of these containers shall be discouraged because they tend to
develop leaks with time.
 Do not mix chemicals unless they are mixed in the process bath.
Always provide secondary containment when storing chemical waste.
All chemical waste containers must be labeled as follows:
Bath/ Tank name
Start Date
Chemical Name/ Compositions
Chemical Characteristics
Total Quantities Disposed
Storage location


All containers must have a hazardous waste tag attached to it. Incorrect labels must
be defaced.
For solid chemical waste, the material should be double bagged and tightly sealed
preferably with a knot and labeled appropriately
6.0 Record keeping
6.1 Record Keeping Requirements for the electroplating plant.
The following copies of records shall be required to be kept at the plant for continuous review
to ensure safe handling, use and disposal of hazardous chemicals by all the staff in
accordance to Environment, Health, and Safety regulations.
Chemical Safety Manual. The plant shall have a copy of this document, which will be
accessible to all personnel.
Safety Data Sheets (SDS). SDSs will be made available to all employees electronically or by
hard copy if electronic access is unavailable.
Chemical Inventory. Chemical inventory forms shall be kept in the plant for proper
management of the storage facilities.
Plant Safety Evaluations. Records of safety evaluations performed by the safety department
of ProHeli International Services Limited will be kept on file for continuous review and
improvements.
Employee Training. Trainings conducted both internally and externally on safe chemical
handling will be documented in the form of a training certificate, with the name of the
employee, title of training class, date of attendance, and topics of discussion. This
documentation will be maintained in the plant and copies shall be provided to management.
Chemical Exposure Assessments. This shall be conducted and results from these
assessments will be communicated to all electroplating staff and management.
Chemical inspection sheet. This will contain all the inspections information pertaining to
the chemicals under storage facilities. This shall be kept in the plant for effective monitoring
and management of storage facilities.