Safety and security at the workplace and home are essential. In third-world countries, fires due to short circuits and gas leakage are significant factors that contribute to the loss of life. It is observed that most of such incidents happen at migrant workers' temporary residences, where the safety of the workers is compromised. Gas leakage is also a significant problem that needs to be addressed, as workers are exposed to harmful and toxic gases like methane and CO while digging wells, cleaning sewage canals, mining, etc.

The human body is sensitive to a variety of harmful gases and dangerous chemicals found in the atmosphere. If the level of gases surpasses the human tolerance limit, a person may be in danger. The quantity of dangerous gases in regions where people live, such as industrial areas, near gas wells, and also in houses, must be detected and measured by a gas detection system. Some of the gases, like methane, are odorless, due to which gross damage may be caused before their influence is detected on the sensory organs. The recent incident in Kuwait resulted in the loss of 49 Indian lives, including a family with 2 children. Investigations of the incident reveal that the fire occurred in the early hours of the day due to a fire in the kitchen that had quickly spread to all the floors of the apartment silently. It is evident that there is always a risk of leakage whenever gas is used, threatening human lives and property [1], [2].

The help of technology is needed to prevent these potential dangers in the form of early warning alerts to ensure that enough time is available to prevent potential dangers [3]. In pipelines, gas transfer and gas leakage are inevitable, as there is a necessity for joints and other transmission components. Gas leakage up to a specific mass level can be ignored; however, it is essential to raise an alarm if it surpasses specific threshold values. During training in the oil and gas industry, the problem was mainly identified at the connection of gas valves. Internet of Things (IOT) can be utilized for efficient and easy monitoring of gas leakages continuously and from any distance [4], [5].

The Internet of Things is the interworking of physical devices such as household appliances with sensors and network connectivity, electric vehicles, etc., which enable communication and the exchange of data, and perform any action as required. In the past, developing an IOT solution required deep technical expertise across the domains of electronics, networking, and software personnel [6]. Today, the advent of plug-and-play models, cloud integration, and a strong knowledge base in the form of YouTube, ChatGPT, and forums enables individuals or small teams to build scalable, functional IOT products quickly at a low cost. The development of various gadgets working with IOT functionalities ranges from home furnishings to sophisticated industrial machines. Healthcare, Agriculture, Traffic monitoring, Safety management, and environmental monitoring are just a few of the areas where IOT has become more significant [7]. Persistent continuous monitoring without human intervention is required for improving the quality of life. Advanced technologies available today, such as the application of AI, ML, and Edge AI chipsets, have made significant breakthroughs in analyzing, understanding, and taking appropriate action without human intervention [8], [9]. The following critical factors contributed to the development of IoT science in today’s scenario.

Expensive hardware with limited options, such as storage and computation efficiency, has been replaced by low-cost, highly efficient microcontrollers such as Arduino Uno, ESP32, and Raspberry Pi.

IOT systems in the past were hand-wired, unlike today's availability of networks to connect through Wi-Fi, BLE, LORA, etc.

Programming IoT projects involved complex C/C++ code without the help of any libraries. Today, the availability of libraries online and simple programming techniques with Arduino IDE, having additional compatibility to connect ESP systems, has empowered developers/freelancers to explore any project and convert it to reality.

IOT projects in earlier days required web development skills, whereas today user-friendly applications and dashboards with drag-and-drop means are available for easy integration between various hardware and software components, as well as with the external environment.

The availability of cheap microcontrollers such as ESP32 and NodeMCU with WIFI and Bluetooth capabilities has given an advantage to the developer to operate things anywhere in the world with the help of Backend as a Service (BAAS) from cloud services.

The time required for development in earlier days would range from weeks to months. In contrast, today, with abundant literature available online, the time required from conceptualization to a realistic product has reduced to days.

This paper presents two types of development of Gas Sensors: 1) a gas sensor operated by an Arduino microcontroller for household security, and 2) a gas sensor operated with NodeMCU to send push notification alarms of gas leakage anywhere in the world, through a third-party application, irrespective of the network. The paper intends to create broad awareness in the development of these IOT projects with minimum hardware and software knowledge [10].

This paper helps in easy understanding of the development of the Gas sensor alarm system, both in the domestic environment and while away from home, irrespective of internet connection. The hardware components and their integration with software are relatively straightforward. The cost is as little as twenty USD. The Future scope is that entrepreneurs can also manufacture this device with a 3d printing casing, which can fit all the hardware.

The authors sincerely appreciate the valuable contributions and support provided throughout this research.

No specific funding was received for this research.

The data used in this study are available from the corresponding author upon reasonable request.