risk analysis of chemical substances in an industrial unit – a new … · 2014. 5. 19. · epoxy...

Risk analysis of chemical substances in an industrial unit – a new tool for prevention

E. C. Alexopoulos, S. Kokkini, E. Kleidona & S. Sarvanidis Hellenic Shipyards S.A., Scaramanga, Greece

Abstract

Accidents involving chemical substances are frequent in industry. Burns on various body sites and toxic inhalation are some of the effects related to accidents involving chemical substances. The aim of this study was to estimate accidents implicated by the handling of chemical substances in a shipyard industry during the last decade. Methods: A retrospective epidemiological study was performed in the shipyard industry from 1995 to 2004 concerning chemical accidents. Data were retrieved through the archive of the Occupational Health Department (OHD), including information on time and place of the accident, description and severity and, the body site affected. Results: From 50 incidents recorded in the whole period, one third concerned dermal burnings and another third eye splashes. It is worth mentioning that the 1995 records included an incident involving 24 workers who inhaled burning fumes, hopefully without serious health effects. Conclusions: Our study indicates that during the period 1990-2004 in an industrial unit of 2000 employees, there were few and mild accidents. Nevertheless, the incident with the 24 affected workers gives strong evidence that chemical substance management could turn into a real tragedy. Employers have to take measures of prevention and early detection because, apart from legal obligations, in most cases, interventions required minimal investment. In order to provide the basis for optimal actions, the OHD has to investigate and evaluate all the incidents and to implement frequent educational programs. A new monitoring system of dangerous gases is presented. Keywords: risk assessment, occupational health, accidents, chemical substance, gas free, shipyard, toxic inhalation, monitoring and prevention.

© 2005 WIT Press WIT Transactions on The Built Environment, Vol 82, www.witpress.com, ISSN 1743-3509 (on-line)

Safety and Security Engineering 887

1 Introduction

In the shipyard industry, workers are frequently exposed to physical hazards including the following: extremes of heat e.g. when welding or burning in confined spaces; cold, wind, rain; possibility of oxygen deficiency when working in tanks, boilers, double bottoms etc; ergonomic problems associated with strenuous working postures and handling awkwardly shaped or heavy materials; noise and vibration; Ionizing and ultraviolet radiation, radio waves and laser beams; Electricity; Airborne particles endangering the eye. In addition they are exposed to various chemicals including oil and rust removers, descalers, carbon removers, acetylene, propane, carbon dioxide (CO2) etc. Among the chemical hazards which give rise to health risks the more common are:

1. The gases used in welding, burning and heating metal: acetylene, propane and excess oxygen. Carbon dioxide used in gas-shielded welding and its breakdown products. Fumes from welding and burning may include ozone and the oxides of nitrogen derived from the effect of heat on the air. Fumes from the vaporization of electrodes, fluxes, surface coatings and parent metals. Parent metals containing zinc, cadmium, aluminium and stainless steel involve specific problems;

2. Vapors from the solvents and thinners in paints like toluene and xylene, epoxy resin curing agents, and isocyanates in polyurethane foam;

3. Dusts from asbestos insulations or associated with shot blasting; 4. Specific toxic chemicals in lead paint, organo-tin and copper in

antifouling paints, epoxy resin systems, oils, pigments and surface coatings in general.

Figure 1: Mean annual employment force of shipyards.

Various job specialists in industry are exposed to chemical substances. Sand Blasters, Painters, Boiler-Makers, Chemical Engineers, Flame Cutters, Mechanics, Platters, Pipe-Plate-Propeller fitters, Ship Cleaners, Marine Chemists, Sub Foremen, Welders and many others. Huge quantities and various

3018

2508

2117 1990 1979 2008 2001

14501620

1471

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

Year

Tota

l em

ploy

ees


888 Safety and Security Engineering

kinds of chemical substances enter in the shipyard industry on a continuous basis. In most occasions it is very difficult for anybody involved to have a good idea of the possible adverse health effects and the other hazards originating from the management of chemicals.

2 Methods

Information on health consequences associated with the chemical substance handling in our study are based on accident records of the Occupational Health department (OHD). Data were collected for the period 1995 to 2004. Monitoring of accidents extends to all casualties but in this study incidents needed additional care (hospital or laboratory exams) were included. The reason was that monitoring of severe accidents has been more reliable and detailed throughout the study period. The number of employees of shipyards in the period under study varied as appears in Figure 1. Between April and August 2004, autopsies were carried out in the case of a chemical accident by the team project in addition to investigations performed by safety engineers.

3 Results

Firstly all cases of accidents needing external care are presented and compared with those involved chemical substances. Table 1 shows the annual incidence of accidents per 100 full-time employees during the study period. Accidents recorded involved the most serious ones i.e. those that needed hospital care or laboratory exams like x-rays, blood exams etc.

Table 1: Incidence of accidents per 100 full-time in shipyard industry the period 1995-2004.

Year Accidents

n Total workforce Incidence per

100 employees 1995 121 3018 4.01 1996 100 2508 3.99 1997 114 2117 5.38 1998 95 1990 4.77 1999 97 1979 4.90 2000 79 2008 3.93 2001 58 2001 2.90 2002 57 1471 3.87 2003 67 1450 4.62 2004 86 1695 5.07



It was observed that incidence varied between 2.90 (2001) to 5.38 (1997) accidents per 100 employees. The lower incidence in 2001 is probably due to the reduction of work and downsizing of the company due to the expected new ownership. An additional factor might be the strict monitoring system begun on 2002. A significant number of accidents (not presented here) concerned subcontractors´ employees. It is worth mentioning that monthly visits ranged from 350 to 600 paid by shipyard employees. Most of them concerned requests for mild anti-inflammatory drugs and simple nursing interventions like blood pressure and glucose measurements. Subcontractor employee’s visits account for up to one fifth of the daily jobs and included mainly provision of first aids. Absenteeism in the shipyard industry was estimated to be around 2.5% of total employment time. Total work time reached 2.5 million hours or 1750 hours per worker in 2002. As a raw estimation, absenteeism due to illness cost more than 25 million Euros. The mean duration of absence per individual was 5-7 days. The most common causes of absenteeism were respiratory disorders followed by musculoskeletal disorders. The last caused three times longer duration of absences than did respiratory disorders. Cardiovascular disorders had also a significant impact on absenteeism since they caused long-lasting absences. In Table 2 incidences of chemical accidents are presented for the period under study. Almost 5 severe incidents per year involved chemical substances have been monitored in OHD for the last decade. Incidents are equally distributed between burns of eye and skin and to a lesser degree causing toxic inhalation, irritant and acute allergic dermatitis.

Table 2: Incidence of severe chemical accidents in the shipyard industry 1995-2004.

Year Eye chemical burnings

n

Skin burns

n

Toxic inhalation

n 1995 2 2 1996 3 1 1997 1 1 1998 2 2 2 1999 2 2

2000 2 2 2001 1 5 2 2002 1 2003 4 4 2 2004 4 3 Total 19 19 12



In our study most of these accidents did not result in serious health effects. In almost all cases, employees returned to job after 1-4 days or even the same day. In one incident which happened in 1995, 24 individuals inhaled gases of fire. In this incidence blue collar workers and fire safety employees inhaled burning fumes during smoke releases in confined spaces of an Lpg boat. It is anticipated that gases included NH3, H2S and CO but the release did not last more than an hour and this prevented serious health effects. Besides that another 49 incidents were recorded in the study period, one-third concerned skin burns and the other third eye splits (Table 2). It should be noticed that recording might underestimate even the number of severe accidents, owing to the fact that there was always the possibility for an employee to search for medical care without informing OHD. But we strongly believe that these cases were extremely rare. By investigation of last year’s accidents and systematic autopsies many useful remarks and observations were produced concerning mainly personal protective equipment usage, education and experience, job organization, labeling and others. The mentality of workers can also constitute an important parameter of hazard. For example in one autopsy at turnery the person in charge for chemical cleaning while he was aware and he was educated for the necessity of protective respiratory equipment, he used them only in special cases where he judged that the danger of inhalation of chemicals was higher; for example in increased wind velocity. Some of the workers did not use PPE, especially safety glasses, plastic boots and special mask in order to avoid contact with skin, eyes and inhalation of dangerous substances. They did not wear plastic apron above the cotton clothes. In a few cases the replacement rate of PPE and keeping and cleaning were problematic. During work time some employees had parallel activities such as smoking and, eating even though the last was observed only in one case. It was worth mentioning that all employees had been informed that handling of specific substances like easily flammable ones might be extremely dangerous and any other activities during chemicals management have to be strictly avoided.

4 Conclusions - a novel tool for prevention According to the study observations it seems very difficult to change personnel attitudes especially for the most experienced ones. In any case a more intense program of education has to be implemented, and the necessity of following rules and legal obligations has to be strongly emphasised. Individuals should always be informed and be aware of chemical hazards used, on their toxicological effects, on first aids and the proper way of use PPE. Material Safety Data Sheets have to be available for all substances used. Recycling, disposition and storage of dangerous materials have to follow strict rules and expertise. For example, the storage area should be cool and sufficiently ventilated while there must be special labelling for workers protection. Receptacles should be kept in separate cabinetries in order to avoid danger of substance mixture. Tidy, easily accessible and clean areas are recommended.



In order to avoid hazardous environments various actions have to be implemented. An important parameter of these actions is an effective and continuous monitoring of dangerous areas in order to prevent human exposure and to take immediate actions when it is needed. When lives and property are on the line, the quality and timeliness of the information you use to make decisions is critical. In an emergency, every moment you delay in taking action can increase the potential for damage or even loss-of-life. The availability of real-time data from remotely located measurement and security devices has the potential for totally redefining the type, timeliness and quality of the information used to make many types of on-the-spot decisions. Two of the writers of the present study (ECA & SS) were members of the scientific team in a study begun April 2003. The aim of that study was to produce a system to monitor the vapors – gases inside enclose areas or anywhere in a continuous base. Gas Net Remote (GNR) is such a system which monitors dangerous gases inside vessels in a continuous basis and would be open to the public from May 2005. The information is wirelessly transmitted by means of a built-in radio frequency (RF) module to a host controller located exactly where the information needs to be evaluated (e.g. control room, fire safety and first aids departments etc.). The location where the readings are displayed and interpreted can be literally anywhere on earth where real-time information is needed to make critical decisions. GNR could monitor physicochemical parameters as flammable, toxic, lack of oxygen, temperature, pressure etc (Figure 1-2).

TERMINAL

GAS COUNTER

CENTRAL STATION

Figure 2: Remote gas detection.



The measurement is transmitted on line to a PC with the GNR Software and could: • Continuously displays status and gas concentration.

• Send alarms to mobile phones.

• Keep sequential records for further analysis.

• Could initiate predefined response actions (start up of ventilation, shut down

if pumps or valves etc).

• Replays history files, exports them to spreadsheets for further analysis and

origination of crisis management procedures and preventive risk analysis.

Our study shows that there is significant hazard originated from management of chemical substances in the shipyard industry. In most cases casualties were limited but we also monitored an incident that proves that the handling of chemical substances can lead to a real tragedy. Occupational Health Department and Safety engineers in order to provide the basis for optimising preventive measures should record and evaluate all accidents and gather data on workers health symptoms, needs and subjective complaints. Moreover OHD has to inform for hazards, to educate on handling, to give guidelines and take actions minimizing the risks, to educate and train employees on first aid. Workers attitude and beliefs have to be faced by respect but also professionalism. One of the most important clues of this retrospective study was that the consequences of chemical accidents could be exceptionally serious, underlining the necessity of preventive measures but also the proper organization and function of first aids and fire safety departments. Prevention, early detection, and the least consequences might be the policy against hazardous environments including chemical substance handling.

References

[1] Ladou, G., Occupational and environmental medicine, International edition by Appleton & Lange, 1997.

[2] World Health Organisation (WHO). Assessing the health consequences of major chemical incidents, Epidemiologican approaches, Regional Publications European series, No 79, 1997.

[3] SPSS 10.0 (1999) Syntax reference quide. Chicago [4] NIOSH, www.cdc.gov/niosh/ [5] EBZ, www.ebz.gr [6] Encyclopaedia of Occupational Health and Safety, International Labour

Office, Geneva, Third (revised) Edition, volume 2 L-Z, 1983.



risk analysis of chemical substances in an industrial unit – a new … · 2014. 5. 19. · epoxy...

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