• Workers need guidelines, hazard prevention training
• Lapses in standards including proper training and standard protective gear such as hard hats/safety gloves/safety glasses/arc-flash clothing

Since accidental electrocution is an expected occupational hazard for solar panel workers, with the rapid growth of the solar panel industry in Sri Lanka, it is important to update workers to prevent such accidents and untimely deaths, via guidelines and hazard prevention training.

These observations and recommendations were made in a case report on ‘A rare case of electrocution due to direct current (DC) generated by a solar panel’ which was authored by C.D. Karunatilake, A.M.A.T.R.K. Alagiyawanna and C.K. Rajaguru (all attached to the Ragama Colombo North Teaching Hospital's Judicial Medical Officer’s Office), and published in the Sri Lanka Journal of Forensic Medicine, Science and Law's 16th Volume's Special Issue, in May of this year.

Workplace electricity accidents are a common occupational hazard in developing countries like Sri Lanka, owing to improper occupational training and the lack of safety measures (the Public Utilities Commission of Sri Lanka's ‘Electrocution analysis in Sri Lanka 2023’). Electrocution by direct current (DC) cases are scarcely reported in the local setup. In contrast to alternating current (AC), DC causes less harm at similar voltages. For DC to produce a significant bodily injury, it should be a high-voltage DC (HVDC) electrocution. 

Case history

In a case of electrocution by DC, a solar panel worker got electrocuted while attaching a series of solar panels in an industrial setting. He lacked proper training, and no personal safety measures were employed. A postmortem examination was performed, which revealed classic features of electrocution with extensive burn injuries. A 19-year-old male solar panel worker accidentally electrocuted himself while connecting a series of solar panels in an industrial setting without proper protective equipment. Co-workers heard an explosion and found a junction box of a solar panel on fire and a shattered solar panel, with the worker lying supine in the vicinity.

He was pronounced dead at the scene, and the body was brought to the mortuary for a postmortem examination. Torn-off garments were seen over the right arm, the right side back of the chest, and the right gluteal (buttock) area. A typical Joule burn with a collapsed blister was seen over the right palm with a clenched fist, which was the entry point. Second-degree burns were seen involving the right distal forearm and the right arm up to the axilla (armpit). Axillary hair was partly singed. The crocodile-skin appearance due to the arc burn was seen over the right mid-forearm up to the elbow joint.

A third-degree burn was seen over the left gluteal region, underneath the burnt and torn clothing. 

Skin sections from the area of burns showed the elongation of cells of the lower layers of the epidermis with micro-blister formation. A conclusion of death by electrocution was made, taking into consideration the scene and the postmortem findings, the toxicological analysis, and the histological examination.

Discussion 

The severity of electric injuries mainly depends on the voltage and amperage of the current, the type of current (AC/DC), the resistance provided, the duration of contact, the pathway of the current through the body, and environmental factors.

AC is four to six times more likely to cause death than DC, partly due to its hold-on effect and increased ability to cause cardiac dysrhythmias (E. Greenland's ‘Electrical energy in home’).

The physiological impacts of AC and DC are different (All About Circuits' ‘Physiological effects of electricity’): the threshold of perception, the let-go threshold, the threshold for ventricular fibrillation, and life-threatening voltage. 

As long as solar panels are exposed to light, they produce potentially lethal amounts of DC electricity (DC danger zone) (J. Foran's ‘Solar panels and the DC danger zone – Reducing risk factors – Part One’). In this case, more than 10 panels had been connected in a series, generating a current of 10-13 ampere and a voltage of 500–1,000. The high amount of DC travelling in a one-way direction creates a strong contraction when it contacts the body, making it difficult to break free. Any attempt to break the load from the source may result in the current arcing and causing a spark lesion. 

Multiple spark lesions give rise to a crocodile skin appearance. At 1,000 volts, the current will jump a few millimetres, and at 100 kilovolt, about 35 centimetres, producing a very high temperature (4,000° Celsius) (P. Saukko and B. Knight's ‘B. Knight’s Forensic Pathology’).

Most deaths occur due to cardiac arrhythmia (ventricular fibrillation) as a result of the current passing through the heart. The pathway of the current will depend on the relative resistance of potential exit points and tends to take the shortest route between the entry and exit points. Since this worker had worn protective shoes, the current was thought to have entered through the right hand and exited through the left buttock.

A less common mode of death is where the diaphragm and intercostal (between the ribs) muscles get paralysed due to the current passing through the thorax. These deaths occur due to the cessation of respiration, leading to hypoxia, where signs of congestive heart failure can be found. Rarely can the current enter through the brain, paralysing the brainstem and ultimately leading to cardiorespiratory arrest. In this case, there is a high probability of cardiac arrhythmia being the mode of death.

Non-electrical trauma also accounts for a considerable number of electricity-associated injuries. Falling from heights or being flung over after being electrocuted can result in fractures and other life-threatening injuries.

Regarding cutaneous electric marks, there may be instances where no skin lesions are found at the entry and exit points. Therefore, it is important to obtain a detailed history regarding the incident, do a proper scene visit, and conduct a thorough postmortem examination, including toxicological and histological analysis, before confirming death by electrocution. Deaths due to electrocution can occur without any external or internal signs, highlighting the importance of excluding other possible causes of death.

This 19-year-old worker was employed without proper training or standard protective gear such as hard hats, safety gloves, safety glasses, and arc-flash clothing. This emphasises lapses in standards and legislation of the solar industry in Sri Lanka, which may be in part due to its rapid growth and high demand (J. Foran's ‘Solar panels and the DC danger zone,’ and Report Linker' ‘Sri Lanka Solar Energy Industry Outlook last year [2024]–2028’). Finally, compensation for the next of kin of the deceased through workmen's compensation is a matter to be addressed.

Conclusion 

HV and high-amperage electricity is deadly, whether from an AC or DC source.