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Before trying to understand Hypothesis Testing and Experimental Designs, we should be conversant with the concept of Probability Distribution.

5.1 PROBABILITY DISTRIBUTIONS

Let us look at an example to grasp the essence of a probability distribution. Let us rotate a pair of dice and observe the sum by totalling the numbers that turn upon in both the dice. Let us call this sum by a random variable X. When the first dice shows up number 1, the second dice could show 1, 2, 3, 4, 5, or 6. Likewise, when the first dice shows up number 2, the second dice could show 1, 2, 3, 4, 5, or 6. If we continue the experiment this way until all the possibilities are exhausted, the sample space will contain 36 elements. The distribution that can be observed will contain a sum = 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12. The starting sum will be = 2, because when both the dice show the number 1, the sum 1 + 1 = 2. Likewise, the maximum sum in the distribution will be 12, when both the dice show up a number 6. If we write the values of the random variable (sum) with associated probabilities, it is called a probability distribution.

For any statistical analysis, the required primary data are usually collected by the census or sampling methods. In the census method, the data are collected from all the individuals. E.g., If we want to study the weight of 100 cows, we have to make use of all 100 cows for data collection. That is, we collect data from the entire population or universe. However, in the sampling method, the data are collected from a small group of the population which is termed as the sample. A sample is a portion of the population selected to represent the population. E.g., we collect data only from a sample of cows, say 20 cows drawn from the population.

3.1 MEASURES OF CENTRAL TENDENCY (AVERAGES)

When data are presented in raw form or in the form of frequency distribution, they fail to provide a general idea of the data under study. The general idea of statistical methods is to condense the raw data into a form that can convey some meaningful characteristic(s) of the data. Though classification simplifies the data and improves the understanding of the main characteristics in the data, it is still difficult to remember. In any distribution of data, values of a variable may tend to cluster (or concentrate) around a central value. The data must be condensed into a single value. Such presentation of data is called a Central Tendency and the measures devised to consider this tendency are known as Measures of Central Tendency.

An average condenses a frequency distribution or raw data and presents it in a single representative number. It is that single value which is considered as the most representative or typical value for a set of values. Such a value usually lies somewhere near the centre of the group. That is why, an average is usually referred to as a measure of central tendency. It is located at a point around which most of the other values tend to cluster and therefore it is also termed as a measure of central location.

Statistics is defined as a discipline that includes procedures and techniques used to collect, process, and analyze numerical data to make inferences about the data. The word statistic is used as a singular, denoting the numerical data. Statistics are the numerical quantities calculated from sample observations. Here, the word statistics hence is plural. Basically, statistics is defined as the statistical data (in the plural sense) and also as statistical methods (in the singular sense). A clearer and more precise definition is that ‘statistics is the study of methods and procedures for collecting, classifying, presenting, analyzing, and interpreting data to make scientific inferences from it’. Bio statistics is the science dealing with the application of statistical methods to the problems of biological sciences.

2.1 FUNCTIONS OF STATISTICS

a) To present the facts in a definite form: If the data or results are given in numbers, rather than in qualitative statements, they will be more useful. The statements like ‘there is a considerable amount of unemployment in a country or the human population in a state is increasing at a faster rate’ are not in definite forms. The statements should be in definite form like there is a 15 percent unemployment in 2023 or the population is increasing by 5 percent every decade.

Human life on the earth has been intertwined with the fabric of crops and livestock for its sustenance, since time immemorial, for food and protection against the vagaries of nature. When agricultural and livestock production systems began to change in the 1950s, from traditional extensive systems to semi-intensive and intensive production systems, diseases of rural farm enterprises became challenging. Especially, the emerging diseases in livestock continued to demand more and more investments for ensuring food safety and security. Despite significant progress made in the recent past in reducing the prevalence of animal diseases, there is still an increasing concern over the losses associated with diseases of economic importance that result in production inefficiency. The scientific foundation for the discipline of animal health economics was laid by Morris (1969) and further steps were taken by Ellis (1972) to economically evaluate the Swine Fever eradication programme in Great Britain using cost-benefit analysis, Martin Hugh-Jones (1975) to specialize in GIS to model diseases and assessed the economic impact on production by infectious diseases, James and Ellis (1978) to use the same tool for FMD control programme, Renkema and Stelwagen (1979) to evaluate the replacement rates in dairy herds, Renkema (1980) to analyze the economic aspects of diseases in animals, Ellis and Putt (1981) to suggest the epidemiological and economic implications of FMD vaccination programme in Kenya, and McInerney (1983) to analyze the economics of animal diseases in dairy cattle, the multidisciplinary field of animal health economics was not amply exploited especially in developing countries to assess the extent of livestock disease losses (Ngategize and Kaneene, 1985).

ICAR-NDRI, Karnal is running a Kisan Seva Kendra at village Lalukheri of district Muzaffarnagar (UP) to cater the requirement of the farmers for frozen semen doses, crops seed and mineral mixture of villages around the center. This centre was established in year 2005; it started fully functioning in 2015. This centre is providing service to the farmers in ~25 villages around the centre. It provides frozen semen doses of high genetic merit bulls with the aim for making improvement in genetic potential for higher milk production of dairy animals of farmers in villages around the centre. The centre is also making available mineral mixture for improving fertility of dairy animals and also making available fodder crop seed to the farmers for growing quality fodder for their dairy animals. Kisan gosthis and farmers awareness camps are also being organized to increase farmers’ awareness regarding benefits of rearing high producing dairy animals and feeding them balance ration for improving their production and reproduction performance.

Since 2015, center has organised ~35 meetings for farmers awareness for adopting scientific techniques/practicesfor dairy husbandry and animal health checkup camps in ~25 villages for improving production and fertility of dairy animals. The maximum numbers of progenies so far, through the use of frozen semen doses from the centre, have been produced of dairy cows and buffaloes in the village- Bhorakhurd (300), Sonjanikheri (440), Alipur (300), Sotta (250) and Sallakheri (250), total 1540 calves.

Intensive farming operations are particularly vulnerable to an increased risk of biohazards due to their densely populated livestock and close confinement. This increased animal density creates an environment where diseases can spread rapidly if not adequately managed. To mitigate these risks and safeguard the health and productivity of dairy herds, stringent farm biosecurity measures are essential. Farm biosecurity, a comprehensive framework of preventive measures and protocols, has emerged as a pivotal strategy in ensuring animal health and curbing the rise of antimicrobial resistance (AMR). By prioritizing biosecurity, dairy farmers can maintain a healthy and disease-free environment for their animals, ultimately ensuring the quality and safety of dairy products while promoting sustainable and responsible farming practices. In recent years, the interconnected challenges of animal health and AMR have prompted a re-evaluation of agricultural practices and disease management strategies.

What is Farm Biosecurity?

Farm biosecurity refers to the set of practices and measures employed to prevent the introduction and spread of infectious diseases within animal production systems. It encompasses a wide array of strategies, ranging from physical barriers and hygiene protocols to monitoring and surveillance programs. The core principle of farm biosecurity is to mitigate the risk of disease incursions by minimizing the exposure of animals to pathogens, thereby preventing outbreaks and reducing the need for antimicrobial interventions. This strategic approach can be broadly categorized into ‘external farm biosecurity’ and ‘internal farm biosecurity’, each addressing distinct aspects of disease prevention within the farm environment.

Animal diseases on livestock farms can have significant impacts on animal health, farm productivity, and economic sustainability. Effective disease management and prevention strategies are crucial to minimize the risk of disease outbreaks and their consequences. Managing animal diseases requires a proactive and collaborative approach involving farm personnel, veterinarians, and animal health authorities. By implementing a combination of prevention, early detection, diagnosis, monitoring, rapid response and control measures, farms can effectively manage and mitigate the impact of diseases on animal health and farm operations. Outlined below are several prevalent animal diseases that can affect farms, along with prevention and management strategies.

Haemorrhagic Septicemia (HS)

It is an acute infectious disease of cattle and buffaloes characterized by sudden onset, high fever, edematous swelling of subcutaneous tissues particularly under the neck, pneumonia and fatal septicemia. HS is highly infectious OIE enlisted disease caused by two specific serotypes of Pasteurella multocida, the Asian serotype B:2 and the African serotype E:2. It causes huge economic losses to dairy farmers of Asia and Africa due to high morbidity and case fatality. The outbreaks of HS are quite common in North region of the country

Mastitis is a consequence of interplay between the infectious agents and managerial practices. The mammary glands of cows are frequently exposed to potential pathogens, but on most of the occasion, cows get mastitis because their immune systems are not adequate to prevent infection. Mastitis is an inflammation of the mammary gland in response to injury for the purpose of destroying or neutralizing the infectious agents and to prepare the way for healing and return to normal function. The average incidence of subclinical mastitis has been found to be 49% in cows and 28% in buffaloes. Similarly, clinical mastitis is prevalent in 7% of cows and 4% buffaloes. Besides this, 17% of the cows and 8% of buffaloes have been suffering from various udder and teat lesions such as udder/teat warts, bovine ulcerative mammilitis, udder impetigo and teat chaps etc. These lesions pre-dispose the animal to mastitis and cause a great discomfort at milking and hence markedly decrease the milk yield. The economic losses due to mastitis worldwide have been estimated at $35 billion. Current annual economic losses due to mastitis in India have been estimated to be Rs. 7165.51 crore that include Rs. 4151.16 crore and Rs. 3014.35 crore due to subclinical and clinical mastitis, respectively. Mastitis causes a reduced milk production, not only at its occurrence but throughout the rest of the lactation, increases the risk of new cases of mastitis and increases the risk of culling. Besides, mastitis impairs the quality of milk and milk products. Approximately 70-80% of losses are due to subclinical mastitis. Subclinical mastitis is also important due to the fact that it is 15-40 times more prevalent than the clinical form. It usually precedes the clinical form, is of longer duration, difficult to detect and constitutes a reservoir of micro organisms that lead to infection of other animals within the herd.Besides this, presence of mastitis causative organisms and antibiotic residues in milk following therapy of mastitis poses a major threat to the consumer health. Mastitis results in increase in the somatic cell count (SCC) and bacterial load of milk. The European Union has set up a threshold of 400,0000 cells/ml of milk from healthy quarter of a cow. The high SCC in mastitis milk has lipolytic effect on fat and there is increased tendency for rancidity of milk and milk products. Also, the mastitis milk with total bacterial count of more than 100,000 cfu/ml could release hydrolytic enzymes, which spoil the milk and milk products. It has been also observed that mastitis milk inhibits the growth of starter bacteria and results in decreased cheese production.

Reproductive problems in bovine dairy farms can significantly impact the productivity and sustainability of the cattle and buffalo industry. Challenges such as diminished conception rates, delayed age at first calving, prolonged calving intervals, and higher embryonic losses have comprehensive implications, resulting in economic setbacks and impeding genetic advancements. These intricate problems are attributed to a combination of factors encompassing deficient reproductive management strategies, inadequate nutritional provisions, suboptimal breeding methodologies, the prevalence of infectious diseases, and the impact of environmental stressors. Inadequate management of the estrus cycle and mistimed insemination practices underscore the significance of effective reproductive management. Poor nutritional support can detrimentally affect the onset of puberty, compromise the quality of oocytes and embryos, and usher in an overall decline in reproductive performance. The presence of infectious diseases not only intensifies difficulties in achieving successful conception but also amplifies the rates of embryonic as well as pregnancy loss.

Additionally, environmental stressors, particularly heat stress, can disrupt estrus patterns, impede oocyte development, and hinder embryo growth. Consequently, addressing these complex reproductive issues necessitates a comprehensive and multifaceted approach. This approach entails the implementation of sound reproductive management protocols to ensure precise monitoring of estrus cycles and timely insemination practices through proper record-keeping. Furthermore, optimizing nutritional provisions tailored to distinct reproductive stages enhances ovarian function, augments oocyte quality, and promotes healthy embryo development. Rigorous biosecurity measures, including strict quarantine practices and adherence to vaccination regimens, play a pivotal role in disease prevention and control within the farm environment. Moreover, the integration of advanced reproductive technologies, such as ultrasonography and embryo transfer, offers avenues for early pregnancy detection and facilitates selective breeding to enhance genetic progress. By amalgamating these strategies, a concerted effort can be made to enhance reproductive efficiency, safeguard herd health, and ultimately support the overall productivity and sustainability of the cattle and buffalo industries.

Field-ready pregnancy diagnostic tests are an important tool for improving reproductive performance in livestock. They help optimize breeding programs, resource allocation, and decision-making processes, leading to better economic outcomes and sustainable livestock production systems. Pregnancy diagnosis is an important tool for improving reproductive performance in livestock for several reasons:

1) Timely management: early and accurate pregnancy diagnosis allows farmers and livestock producers to make timely decisions about the management of pregnant and non-pregnant animals. This includes adjusting feeding regimes, providing appropriate veterinary care, and establishing breeding plans.

2) Optimized breeding programs: In livestock, controlling the timing of pregnancies is critical to maintaining a well-organized breeding program. With accurate pregnancy testing, farmers can identify non-pregnant animals and breed them back earlier, optimizing resource utilization and shortening the generation interval.

3) Resource allocation: early identification of non-pregnant animals helps avoid unnecessary allocation of resources such as feed and health care to animals that will not produce offspring in the current cycle. This efficient allocation of resources is essential to maintaining a cost effective production system.

4) Lower costs: unproductive animals consume resources without contributing to farm productivity. By quickly identifying non-pregnant animals, farmers can avoid the cost of keeping these animals during their non-productive period.

5) Genetic improvement: for livestock programs focused on genetic improvement, accurate pregnancy diagnosis is critical. It enables the selection and promotion of animals with desirable traits for breeding purposes, thus accelerating genetic progress.

Currently, the milk production of country is 221.06 million tonnes (2021 22) and the target is 300 million tonnes by 2023-24. The livestock sector contributed nearly 5.21% of total gross value added (GVA) and 28.36% of the agriculture and allied sectors GVA. Thus, there is a huge gap between demand and supply, therefore with the requirements of better yield from the dairy animals, we need more better and advanced options. Artificial intelligence (AI) is one of such options which can be exploited in dairy industry. Artificial Intelligence can be a game-changer for the dairy farming in India and it can emerge as a tool that empowers farmers in monitoring, forecasting as well as optimizing the farm animal growth. It can predominantly change the scenario of dairy farmers by maintaining the health, physiological and physical conditions of dairy-cows. This knowledge-based technology has a huge potential and could confront the loopholes in dairy farming and thus indirectly can strengthen the dairy industry. In dairy farming AI has multiple applications like monitoring the activities of the dairy-cows, boosting the milk production and farm productivity, detection of mastitis in dairy-cows and developing the smart cow houses powered by image analysis.

AI enables the dairy farmers to determine whether the cow is ill, ready to breed or has become less productive. The AI also sends alerts to the farmer about the change in the cow’s behavior allowing human intervention where needed. Regular 24x7 monitoring of dairy animals is the key for successful dairy farming, however, traditional methods of monitoring relied on visual observation, but it was not very efficient due to the lack of time and human resources. Without AI, it would be almost impossible for the farmer to keep a watchful eye on every cow in the herd. Artificial Intelligence components of the dairy automation system process the collected data to provide insights on the heat stress, change in feeding efficiency and the estrus of the cow. Diseases like sub-clinical mastitis, one of the more common diseases in the dairy industry, cost the Indian dairy industry one billion dollars annually. Eventually, it provides new hope and open prospects for the overall quality and progress in the dairy industry through a profitable business approach in dairy farming

India has a primarily agrarian economy. A significant portion of the country’s land is utilized for agriculture, and many of its agro-ecological regions cultivate a broad spectrum of crops. With a production of 93.9 million tons (Mt) of wheat, 104.6 Mt of rice, 21.6 Mt of maize, 20.7 Mt of millets, 357.7 Mt of sugarcane, 8.1 Mt of fibre crops, 17.2 Mt of pulses and 30.0 Mt of oilseeds crops, in the year 2011-12, it is usual that a massive amount of crop residues are produced both on-farm and off-farm. The country produces approximately 500-550 Mt of crop residues per year in the country. Therefore, landholders are facing difficulties in managing crop residues in the country. The human population has grown four times in the last century. With a projected 9.7 billion people in the world by 2050, worldwide food consumption and the demand for meat and milk are likely to increase by as much as 73% and 58%, respectively. Improved agricultural and industrial practices have contributed to the population boom, which continues to put pressure on food supply to feed a growing population. Huge quantities of food resources will be needed, but again, the crop residues produced at these levels of global production pose major challenges.

Availability of Crop Residues

India produces more than 500 million tons (Mt) of agricultural residue on an annual basis. The quantity of residue produced has grown significantly due to the cultivation of wheat and rice. Crop residue output varies greatly, and the use of these residue is influenced by the crops cultivated, the intensity of cropping, and the productivity across different Indian regions. About 70% of the total crop residues (352 Mt) are contributed by cereal crops (rice, wheat, maize, millets), with rice contributing 34% and wheat 22%. The excess agricultural residues—that is, the residues left over after subtracting the amount used for other purposes—are often burned on the farm. The amount of surplus crop residues available in India is estimated between 84 and 141 Mt per year where cereals crops contribute 58. As an estimate, about 70 MTs of surplus crop residue are burned annually.

As per 20th Livestock Census (2019), Punjab has 1.3% share of India’s total livestock. The share of buffaloes was largest (57.4%) in total livestock population, followed by cross-breed cattle and indigenous cattle. The state of Punjab has about 70.60 lakh livestock in total, comprising of 25.41 lakh cattle, 40.16 lakh buffaloes, 3.48 lakh goats, 0.85 lakh sheep, 0.53 lakh pigs, 0.15 lakh horses and ponies, 1644 mules, 471 donkeys and 170 camels. The share of crossbred cattle increased to 29.3% in 2019 compared to 25.4% in 2012 which signifies that the farmers in the state are resorting to high yielding animals for increasing the milk production. These efforts have led to the highest per capita availability of milk in Punjab which stands at 1271 grams per day compared to national average of 444 grams per day (2021-22), although the share of Punjab in country’s milk production is 6.37%. Punjab is sixth largest producer of milk in India, with production of 14.76 million tonnes (t)/year.

Climate change has emerged as one of the most pressing global challenges of our time, with far-reaching consequences for ecosystems, economies, and societies. This has led to the higher temperatures, changing precipitation patterns, sea level rise and growing frequency and intensity of extreme weather events such as drought, floods, extreme heat and cyclones resulting in disruption of food supply chains. The most critical domains that impact environmental sustainability includes energy, transport, food, waste and water , although there are disparities in the consumption patten of high-income and low income countries. Apart from the food domain (33% of total GHG emissions), meat from ruminants and dairy products constitute the major proportion of carbon footprint. Although only 18% of calories are obtained from meat and dairy products, but they together account for 60% of agriculture’s greenhouse gas emissions and occupy 83% of the world’s arable land. With 18% of anthropogenic greenhouse gas (GHG) emissions, the livestock sector has been identified as one of the primary causes of climate change and the dairysector accounts for around 3.0- 5.1% of the total GHG emissions globally.

Rearing animals has been amongst the most ancient professions of humanity and since the advent of domestication, the livestock keepers have been involved with them to a certain extent on financial, social and emotional fronts and thus have been curious about certain key aspects of the livestock under their care. The curiosity can be defined with the ‘five W and one H’ of questions as What needs to be done (requirements)? When to do that (timing)? Where are they (location)? Why is there a need (rationale)? How will that meet my purpose (state)? The farming community has traditionally been using these attributes for making farm decisions by observing the animals constantly, or periodically at key occasions such as milking. Such monitoring, aided by the wisdom of experience of the generations of farmers, led to the identification of the key events or problems in the health and productivity of individual animals. However, such kind of monitoring requires a deeper engagement in livestock keeping than that is desirable in commercial farming and the decisions/ detections are severely limited by the capability of the observer.

Precision Livestock Farming (PLF) is a term that encompasses the deployment of sensors for the capture of key biological information, the use of algorithms for processing the biological information (data science), systems for making inferences and making decisions based on the processed data (artificial intelligence), interfaces that allow for making use of these data (reporting) and implements for automation (robotics). PLF is intended to optimize the process of animal production, health care and welfare by generating vast real time information to be used in various ways. There have been many systems being tried and found fit for practical applicability; whereas, few systems like geolocation and motion detection are extensively applied.

A laboratory is essential for research work in science and development. Most of the research institutes have dedicated laboratories for researchers and students to conduct experiments, perform research work, as well as to provide hands-on learning/training to students. There are certain rules and regulations laid down by the laboratory in-charge which need to be followed strictly for safety purposes. Some of the laboratories keep ‘safety manual’ for researchers to read before entering into the laboratory to conduct experiments. Whenever safety is compromised in a laboratory, there is increase in risk of unwanted incidents in the laboratory. Storing food/beverages in the same refrigerator where laboratory chemicals are kept may lead to disastrous effects on health. This chapter aims to provide instructions in brief on the things to be performed (Do’s) before and after entering onto a laboratory as well as the things never to be done (Don’ts) in a laboratory for the safety reasons.

Good Laboratory Practices (Do’s)

• P Wear apron/labcoat while working in the laboratory.
• P Use gloves/respiratory mask/fumehood while handling toxic/volatile/inflammable chemicals/reagents.
• P Use pippet or pippetor for safety in transfer of solutions.
• P Protect eyes, face and naked parts of the body from UV radiations. Use safety goggles or face mask/apron.
• P Keep your eyes away from Liquid Nitrogen and use cryogloves while handling it.
• P Arrange all the necessary materials/solutions before starting the experiment.
• P Periodically fumigate/ozonize culture and inoculation rooms.
• P Autoclave all contaminated materials before discarding.
• P Pre-treat gel or solution containing Ethidium Bromide (EtBr) before discarding into laboratory waste-disposal bin, and use gloves while handling them.
• P Burn all the transgenic plant materials in an incinerator after taking necessary observations.
• P Make entry in the designated log-book and clean the instrument after using it properly.
• P Switch-off the instrument after use or when not in use.
• P Wash hands with soap and remove the labcoat before leaving/going out of the laboratory7.
• P Ensure that switches for fans/lights, and water taps are off while leaving the laboratory.
• P Follow the biosafety guidelines suggested for handling and disposal of the hazardous chemical.

Introduction

Several hazardous chemicals, microbes, and techniques like recombinant DNA technology are used for research and development work in research Institutes and universities. Therefore, the researchers, technical, helping and supporting staffs as well as the laboratory outputs must be kept free from contaminations. Thus, biosafety is necessary to prevent unintentional exposure/ release of hazardous chemicals, microbes/pathogens, and toxins to the laboratory staff and environment. Following the biosafety guidelines and ethical considerations are essential to maintain safety standards for the researchers as well as the environment. This chapter deals with various biosafety measures and ethical issues to be strictly followed while working in a research laboratory. The required safety level needs to be determined as per the chemical/biological materials are used in the laboratory to keep the researcher/environment safe for sustainable research and developmental activities.

Biosafety

The term biosafety is used to describe the procedure and policies needed to ensure environmental and personal safety. Biosafety refers to the containment principles, technologies and practices that are implemented to prevent unintentional exposure to pathogens, toxins, or their accidental release into the environment. A fundamental objective of any biosafety program is the containment of potentially harmful chemical/biological agents as precautionary safety measures.

Why Biosafety?

With the increasing number of countries adopting molecular biology tools and techniques in life science research and development activities, especially in the areas of agriculture and medicine, the biosafety issues are gaining importance to ensure biological safety for the public and the environment. Conducting research in safe and sustainable manner is not only a personal requirement but essential collective efforts to ensure biological safety for a clean and safe environment. This requires rules, regulations, monitoring bodies, and awareness among the workers as well as the public. Therefore, biosafety per se is an integral part of laboratory research and requires awareness among the researchers so that biological safety can be well taken care from the grassroot level.

For a researcher, laboratory is another home where he/she spends much time every day. As we take care of cleanliness, safety, and design of our home, we must take care on these aspects of laboratory too. It is the responsibility of the laboratory personnel to ensure cleanliness/safety of the laboratory. Since every laboratory chemical and equipment have the potential to cause harms if not used with appropriate precautions. Hence, as a laboratory user, it is our responsibility to follow the basic safety/biosafety rules and regulations set up by the Principal Investigator of the laboratory, Institutional Biosafety Committee, as well as by other regulatory authorities, if any. We must be aware of the general/personal protective measures, cleanliness and laboratory waste disposal prior to joining a research laboratory. In this chapter we will briefly discuss about personal safety, chemical safety, cleanliness, waste disposal, etc.

A. Personal Safety

1. Personal Protective Equipment (PPE)

Personal protective equipment (PPE) is special arrangement to protect the worker from specific hazards because of using a hazardous substance. PPE does not reduce or eliminate the hazard, but protects the wearer from exposure to hazardous material. PPE should not be reused or brought outside the laboratory as these might increase the risk of spread hazardous material or contamination. Used PPE must be kept inside the laboratory in a designated waste storage area adjacent to the work area.

Introduction

Proper electrical wiring and earthing are crucial for laboratory safety and functionality. A laboratory houses several installations/equipment that demand stable/continuous power supply. Inappropriate or faulty wiring and earthing may lead to significant risks, including electrical shocks, damage to equipment, and even incidence of fire. Therefore, understanding the requirements of electrical wiring and earthing is essential for designing, construction, and maintenance of laboratory. This chapter aims to provide a basic knowledge of electrical wiring and earthing necessary for a laboratory. Importance of earthing in mitigating electrical hazards and ensuring integrity of electrical installations are also described.

Basics of Electrical Wiring

Basic understanding of electrical wiring is necessary for laboratory safety and efficient electrical functioning. The potential difference between two electrical points (negative and positive) is known as Voltage, which drives the flow of electric current. This is measured as volt (V). The rate of flow of electricity in a circuit is known as Current (I), which is measured as ampere (A). Current can be either direct (DC) or alternating (AC). Opposition/resistance experienced in the flow of current in circuit is known as Resistance (R) and it is measured in ohms (Ω). Higher the resistance means lesser the current flows at a given voltage. The rate at which electrical energy is transferred/utilized in an electric circuit is known as Power (P), which is measured in watt (W). The Power can be calculated as the product of voltage and current (P = V × I).

Introduction

We come across a variety of chemicals every day in a laboratory. While some of them are relatively safer, others are extremely hazardous. Thus, it is very important to know the potential hazards that can be caused by the chemicals present in the laboratory and the safety measures needed to be followed to avoid the hazards. Additionally, we should also be aware of the steps necessary to be taken on such hazardous situations. According to IUPAC, a hazardous chemical mean the chemical which has the potential to cause damage in various ways. In a laboratory, there are chemicals that might be irritant, carcinogen, respiratory fibrogen, systemic poison, asphyxiant, flammable, etc. which have the potential to cause hazard to the workers or environment. Therefore, it is important to use appropriate procedure to reduce the risk and protect the health/safety of laboratory personnel, the public and the environment.

Types of Hazards Associated with Chemicals

Chemical hazards: The hazards caused by chemicals can be broadly classified into three categories.

1. Health hazard: This is also known as toxic effects of chemical. The risk associated with a chemical in laboratory depends on the extent of exposure and the inherent toxicity of the chemical. Many chemical reactions form the product that might be much more toxic than the reacting chemicals. For example, inadvertent mixing of formaldehyde (a common tissue fixative) and hydrogen chloride results in the generation of bis(chloromethyl) ether, a potent human carcinogen. For most of the chemicals, the route of exposure (through skin, eyes, gastrointestinal tract, or respiratory tract) is more important (Figure 17.1) that must be considered during risk assessment.