Laboratory Waste Management in Nigeria

By Olubukola Betty Olatoye
November 2009

The Author is a Project Coordinator with Berthys Easy Everyday Konsult in Sango-Ota, and a Fellow Member of the Institute of Chartered Chemists of Nigeria. → See also:

Laboratory waste management is important in the sustainable environment plan of the MDG7. Due to the various categories of laboratories namely, medical, forensic, Dop testing, analytical (chemicals, foods and beverages, pharmaceuticals, metals, solid minerals, textiles, leather, tannery, dairy products, petroleum products, plastics, rubber and other raw materials), microbiological, computer and voice training laboratories. Laboratory wastes of varied categories (solids, liquids and gases) both hazardous and non-hazardous are usually generated and must be appropriately handled and disposed, such that it will not constitute hazard to handlers and those that will come in contact with it especially the solid type, during transportation, disposal at dumpsites and also after disposal. This is why laboratory wastes management is important to mitigate against the various relevant aspects that will otherwise make it unsafe to the handler, the people around and the environment. The various categories of the solid generated wastes should therefore be sorted into various categories immediately after its generation to prevent contamination. These various categories must be subsequently treated appropriately before their final disposal at relevant dumpsites, which depends on the various available dumpsites within the locality in which the laboratory is situated. Transportation and site storage of these generated wastes must be done using properly constructed containers suitable for each category of sorted waste, all the procedures for the afore mentioned aspects of laboratory waste management should be put into a policy that has the backing of the management team, to ensure proper implementation of each aspect of enabling a safe handling of the generated wastes from the laboratory, most importantly in the aspects of funding, information dissemination, personnel training, HSE issues, site and transportation containerizing, preliminary treatment before disposal, timing of regular removal from site to final disposal site and record keeping. A sustainable laboratory waste management action plan in establishments will ensure that the laboratory wastes are handled accordingly, given attention and relevance at all times, government regulatory guidelines should also be put in-place to mandate laboratory operators to comply.

A Laboratory is a facility that provides controlled conditions in which scientific, research experiment and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories. These notably include:

Scientific laboratories can be found in schools and universities, in industry, in government or military facilities, and even aboard ships and spacecraft. A laboratory might offer work space for just one to more than thirty researchers depending on its size and purpose.

Waste: according to Basel convention, it is any substance or objects which are supposed to be disposed or which are required to be disposed by the provisions of law. It can also be defined as products arising from human and animal activities that are discarded because they are no longer useful, they can be solids, liquids or gases. Wastes can also be substances or objects which the holder discards or intend to be discarded by the holder. Wastes can be solids, liquids or gases.

Solid Waste Categories

Household wastes: are generated from residential homes, including those in institutions and schools.

Industrial wastes: are generated from factories, refineries, and filling premises for gases, sewage services, postal or telecommunication services.

Commercial wastes: are from trades and business or sports and entertainment areas, offices, hostels, shops, markets, hotels, institutions, schools etc.

Clinical wastes : any waste containing mainly partly animal or man tissues, blood, drugs, other pharmaceuticals products, dresses, syringes, needles or other sharp instruments, also wastes from medical, nursing, dental, veterinary, pharmaceutical or similar practices for teaching and research purposes and collection of blood for transmission.

Municipal wastes: are wastes collected and disposed off by and on behalf of local authority, in general the wastes consists of mainly household and commercial wastes and wastes from civil amenities waste collection, street sweeping, gully, construction and demolition wastes from local authorities.

Non-hazardous wastes:uncontrolled waste that does not pose any danger to handler or the environment, but may degenerate to hazardous waste if not properly handled and disposed on time.

Hazardous or special or controlled wastes: are any kind of waste that is or may be so dangerous or difficult to treat, keep or disposed off, and special provision is required in dealing with them. They contain substances that are dangerous to life or the precipitates of the wastes have physical, chemical and toxicological properties, these kinds of wastes are subject to concernment note systems. They adversely affect living things and the environment. Laboratory wastes falls into this category of waste.

National Waste Classification System

Wastes can be conveniently grouped accordingly using the following parameters: Waste origin, waste form, legal definitions, industries generating the waste, process generating the waste, waste standard description or main or detailed compositions, waste properties, and label.

Characteristics or Properties of Hazardous wastes:

Basel convention gave various categories of wastes, all of which had been published in the previous IPAN newsletters can be found in the laboratory for analysis and subsequent disposal as waste having been analysed.

These wastes can be further categorized as inactive, low activity, biodegradable, non-biodegradable, scraps, contaminated, health care, plants and animals parts, human parts, glass, planks, leather, asbestos, oil wastes, solvents and chlorofluorocarbons (CFC), air samples, particulate samples, gaseous samples, inorganic and organic, radioactive, explosives, pesticides, sands, and many mixtures of these items. This is why laboratory wastes are highly contaminated special wastes comprising of various components, depending on the type of laboratory and amount of samples of various categories that they receive and analyze regularly. Laboratory wastes thus need treatment and special handling and disposal information.

Chemistry of Wastes

Wastes in form of solids, liquids or gases enters the environment through the various anthropogenic activities of man and via addition into the air, water and soil either directly through emissions into the air, discharge into the water body in wastewater and effluent and also through dumping of solid wastes or indirectly by the after effect of the direct introduction of wastes like leaching at dumpsites, evaporation or wind blowing from waste sites and long distance as well as trans-boundary movement, leakages from tanks, accidental discharges, release from improperly operated treatment plants, storage, disposal facilities and industrial processes and runoffs from dumpsite and other containers during rain or due to busted water pipes and liquid holding tanks situated near them. Wastes are thus transported to other areas and the wastes properties like volatility, contact environment, chemical compositions, reactivity, weather and climatic conditions, solubility etc. also contributes to this movement.

The toxicity of hazardous wastes depends on several factors which includes, the chemical nature of the hazardous waste, the surrounding matrix, circumstances of its exposure, degree of exposure, time duration, and the species in the hazardous waste exposed, those with short lifespan are easily degraded to more or less toxic substances while those with long lifespan are the non biodegradable ones, they remain in the ecosystem for long and tend to wreck more havoc.

Effect of Hazardous Wastes

When air emissions, water effluent discharges and solid wastes are discharged into the environment, the particles from the air eventually settles onto soil, plants, house roofs, water and some inhaled by humans and animals while some are transported far away from the source of pollution the various components of the liquid effluent also gradually collects on the soil, transported to other locations and penetrates soil through percolation, all these also leads to the contamination of the surface and underground water. Solid wastes also contaminates in this manner, by the dissolution, disintegration and biodegradation of the components, in addition to this, the solid wastes emits foul odour and serve as homes for diseases causing vectors, rodents and bacteria, thereby bringing about various kinds of epidemic emergency situations in plants, animals and human that comes in contact with them. The non-biodegradable ones creates further nuisance and serves as homes for disease carrying organisms. The low-biodegradable ones stay in the environment for long and continue to cause health and environmental problems before they finally degrades, these problems ranges from making the ecosystem becomes imbalanced to shortening the life span of living things that comes in regular contact with them, bringing about monumental losses.

Water, Air and Soil pollution makes these chemicals enter the water cycle, food chain, bioaccumulate in humans and other living organisms especially those consumed eventually by man, making it possible to cause cancer and many other life reducing diseases. It also pollutes the environment leading to erratic weather conditions, heat waves, ozone layer depletion, melting of Arctic and the Antarctic ice, bringing about imbalances in the various ecosystems. All these make it important for legislative regulations to be formulated for environmental management by all stakeholders.

Laboratory Wastes

This falls under the various categories of wastes earlier enumerated in the Basel convention categories of wastes; all the materials can be brought into the laboratory for analysis. Laboratory samples can be textiles, pulps, papers, paper products, food products, beverages, refined petroleum products, chemical and chemical products, soaps, glues, fats, waxes, grease, human and animal wastes, rubber and rubber products, plastic products, tobacco products, household goods, telecommunication products, building and construction products, metals and metal products etc.

In reality the quantity of the waste generated from a laboratory is usually small when compared to other household and commercial wastes within the locality where the laboratory is situated, thus they are normally given to waste collectors that carts away other household and commercial wastes in the area, and this wastes are dumped at the same dump site, however because of the level of leftover samples, containers and residues from analysis which can in fact be highly hazardous both biologically, physically and chemically.

Waste Management

Anything else you’re interested in is not going to happen if you can’t breathe the air and drink the water. Don’t sit this one out. Do something. You are by accident of fate alive at an absolutely critical moment in the history of our planet.
Carl Sagon

Waste Management: may be defined as the discipline associated with the control of generation, collection, storage, transfer and transport, processing and disposal of solid wastes in a manner that is in accord with the best principles of public health, economics, engineering, conservation, aesthetics and other environmental considerations.

Waste generation: This encompasses activities in which materials are identified as no longer being of value and are either thrown away or gathered together for disposal. For example, the wrapping of a chocolate is usually considered to be of little value to the owner once the chocolate is consumed and thrown away, especially outdoors. It is important in waste generation to note that there is an identification step, which varies with each individual waste. The quantity of solid waste generation depends upon factors such as standard of living, food habits and degree of commercial activities and the quality of the waste also varies seasonally. According to the study carried out by the Central Pollution Control Board (CPCB) in 2000, in India, for Class I cities, the solid waste generation was about 0.4 kg/capita/day. In other cities, the average solid waste generation was 0.2 kg/capita/day. The quantity of waste generation is directly related to increase of urbanization. The present urban population of India is about 25% and is estimated to go up to 60% in 2025. In India currently about 100,000 metric tonnes of Municipal Solid Waste is generated in a day!

Waste management involve the cradle to grave approach to handle waste, where planning starts from the collection, handling, storage, transportation, treatment, disposal and subjected to local, national and international regulations and legislations as well as after care services like waste stock exchange. Collection can be done in dust bins, plastic bags, nylon bags, dino bins, low wall type shed, built rectangular enclosures and steel depots. Transportation of the wastes in an appropriately constructed container that will prevent spillage, if it’s a liquid, volatility if its very volatile and prevent littering the road as its being carted away is very important to prevent further damage to the people and the environment.

(ESM) Environmentally Sound Management of hazardous waste is the handling of waste in a way that is technically safe without harm to the environment.

Sustainable Waste Management is the continuous plan put in place to ensure that waste generated are properly disposed of at all times such that it will not constitute nuisance to the present generation while also mitigating against the future effect.

Treatment of Hazardous Solid Wastes

Treatment of Hazardous Wastewater

Using an installed secondary treatment plant where the effluent is collected into retaining tank where aeration can be done, and then liming to help to coagulate suspended particulates, followed by collection into another tank referred to as the primary sedimentation tank, here alum or poly electrolyte can be added as well as carbon dioxide to acidify the solution before transferring into a secondary sedimentation tank, chlorination is then done to destroy many microbes, followed by filtration using the sand and activated carbon systems to adsorb other organics and soluble compounds in the effluent, the resulting solution is then transferred into a storage tank where it is subsequently discharged into the receiving body of water via the public drain.

Treatment of Hazardous Gaseous Wastes

The usual method is the fixing of cartridges containing activated charcoal onto the route of passage of the gaseous emissions like in the exhaust, the fume cupboards and the fume extractors.

Sustainable Waste Management in Laboratory

This can be achieved by regularly monitoring the facilities used for making the generated wastes less hazardous, by putting a policy in place where the various aspects of implementation is documented and management commitment is gotten to help to finance all the necessary aspects and also educate and enforce the relevant areas, while also protecting the occupational health of the workforce. This will enable prompt replacement of used up parts and regular services of machineries as and when due.

The Nigerian Practise


Presently the policies on wastes generally have not advanced well enough to incorporate the identification and estimation of the impact of improper laboratory waste handling.
Emphasis have however been placed on medical wastes, some of which may be laboratory generated, for instance the medical laboratory situated within the clinic or hospital. This type of waste has been categorized under the special waste category and action plan for the handling and disposal is being prepared with the assistance of various stakeholders.

Other laboratories must be incorporated into this group and mitigation for storage, handling, transportation, treatment and disposal activities must be documented, implemented and monitored, to achieve this, the use of strategic policy instruments that covers the management, technical (engineering constructions and better handling as well as alternative materials), funding and manpower development, this will help to mitigate the effect of poor handling of laboratory wastes against any possible negative impact on man, other organisms and the environment, this will also mandate the various laboratory managers to play their role as a waste generator responsibly such that violations will attract penalties ranging from sanctions, payment of fines, use of polluter pay principle (PPP), and court sanctions. Some of the guidelines are presently embedded into the S.I.8, 9 and 15 as well as the FMENV. LFN 131. but this is not adequate because of the generalization the statements and thus specific statements must be incorporated into these regulations, guidelines and laws to commit the laboratory waste generators.

Present Day Handling of Laboratory Wastes in Laboratories Attached to Industries and Independent Laboratories.
In most Pharmaceuticals, Chemicals, Agricultural, Metallurgy, Food & Beverages, Cable & Wire, and in deed all industries with in-house laboratories, there is presently no special arrangement for the separation of the wastes generated within the laboratory section,

Solid wastes: these are usually packed and dumped with any other generated solid wastes within the establishment, some microbiology laboratory solid wastes are some times autoclaved to sterilize before final disposal, this depends on who is in charge and if the personnel is experienced and well trained enough to know that this should be done.

Liquid wastes: the liquid effluent usually generated within the laboratories are usually given treatment according to the capacity of the company, some are mixed with other generated liquid wastes of the firm and disposed together, some are given prior treatment in an ETP along with other liquid effluent in the firm with this treatment installation or transferred to general treatment plant for liquid effluent waste, some are disposed via the use of tankers that carts them away to an unknown destination away from the production site. While majority are channeled directly into the public drain for disposal without any form of prior treatment. This is the practice in many laboratories in industries and other independent laboratories as well as in research and institution located laboratories.

Gaseous wastes: air emissions (specially from the fume cupboards, laminar airflow systems, heat, fumes and particulate extractors installed for clean air environment within the laboratory) have not been properly handled in most laboratory settings, in most cases the air control equipment comes with an adsorbent or an absorber (like activated charcoal etc.), this may however never replaced and those eventually replaced may have exceeded their absorptive capacity long time before replacement such that they most times extract directly into open air, thereby contributing significantly to the air pollution within the locality. Some air installations actually extracts into the open air thus having the same effect in terms of polluting the environment.

The Way Forward

With appropriate policy instrument and proper strategic planning, the disposal of generated laboratory wastes can be achieved in no time, considering the level of education, awareness, communication, information dissemination and information accessibility of personnel working within the laboratory. With appropriate funding, allocation of other necessary resources, training and retraining as well as employment of relevant experts to manage, advice, and help to implement the process of laboratory waste management compliance. This will in turn help to achieve good waste management practice in laboratories.

It will be appropriate if government can make a policy and put in place a special arrangement for the wastes to be collected together with many other special wastes which may have been collected in households and other commercial centers, and proper treatment given to them before disposal, therefore public enlightenment, proper information dissemination and multimedia (radio, TV, internet), incorporation into students’ curriculum in various stages of education as well as magazine publications to announce that the various waste and environmental management measures are available for us to adopt based on our local and individual needs so that sorting of wastes to at least hazardous and non- hazardous waste should be done by the waste generator and the various hazardous wastes listed for them to know. A bill to the federal house of assembly for approval should be submitted to legally back this policy, this will ensure that these special wastes are treated and properly handled before disposal at the general dumpsites, in so doing it will be possible to safely use land filled sites for buildings, road and complex constructions as well as for farming purposes.



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