Chemicals constitute a part of everyday life. Approximately 1,000 new chemicals are placed on the market each year, usually found as mixtures in commercial products, while more than 100,000 chemical substances are used worldwide (1). Many of these chemicals may, especially if not properly used, possess hazards for human health and be toxic to the environment.

The hazards of chemicals can be classified based on physical, chemical and ecotoxicological endpoints using criteria developed in the framework of scientific or regulatory processes (2). A number of national and international schemes have been developed over the past 50 years. To avoid multiplicity and confusion at the user level, the globally harmonized system (GHS) for the classification and labeling of chemicals was adopted in 1992 during the Rio Earth summit. GHS includes easily understandable symbols that can be applied in the manufacture, transport, use and disposal of chemical substances (2).

At a European Union (EU) level, two Regulations have been introduced, Regulation (EC) 1907/2006 (REACH) and Regulation (EC) 1272/2008 aimed to effectively handle hazards and risks from chemicals. The new EU chemicals legislation applies to all industry sectors dealing with chemicals along the entire supply chain. It therefore makes companies responsible for the safety of chemicals they place on the market.

The CLP Regulation, which is based on GHS, ensures that the hazards presented by chemicals are clearly communicated to workers and consumers in the European Union through the classification and labelling of chemicals. The industry must establish the potential risks to human health and the environment of substances and mixtures prior to placing them on the market as commercial products, by classifying them using the classification, labelling and packaging (CLP) criteria, in line with the identified hazards. The need to develop harmonized criteria for classification is essential in ensuring effective communication of the risk (3). Hazardous chemicals also have to be accordingly labeled using hazard and precautionary statements and pictograms.

In addition, suppliers established in the EU and placing hazardous products on the market have to provide standardised information to be used only by Poison Centres (Article 45 of the CLP). The Poison Centres provide medical advice in case of poisoning due to exposure to hazardous chemicals or to other toxic agents to the general public and to physicians. Poison centres in the EU answer on average 600,000 calls for support each year. However, EU legislation does not specify the precise information needed for this product notification. Therefore, varying requirements have been developed by each EU member state (4).

Safety data sheets (SDSs) are the main communication tool under the REACH Regulation between suppliers and users of substances and mixtures and it is a regulatory obligation for the industry. SDSs include information on the physical, chemical and hazardous properties of the substance or mixture as well as instructions for their handling, disposal and transport, and for first-aid, fire-fighting and exposure control measures.

The aim of the present study was to assess for the first time, to the best of our knowledge, the level of comprehension of the hazard and risk communication and awareness regarding the safe use of chemicals among Greek professional users and health care specialists eight years after the introduction of the respective EU legislation.

A total of 1,500 individuals (850 industrial workers and professional users of chemicals from 35 different small and medium enterprises, self-employed professionals included, and 650 health care specialists from 6 public and private hospitals/medical centres, 40 private practitioners included), in Athens; Thessaloniki; Larissa; Ionnina; Patras and Heraklion Crete, Greece, were asked to answer an anonymous validated, self-administered questionnaire with 26 close-ended questions from May 2016 to April 2017. The questionnaire was left at the reception desk of the various workplaces, accompanied with an explanatory opening page, where it was stated that the results of the survey were to be published. The return of the completed questionnaire was considered as written consent of the study population. A total of 350 individuals (200 workers and professional users, 150 health care specialists) returned the questionnaire by placing it in a specifically marked receptacle at the reception desk of the various workplaces (return rate 23.3%, in the range of the typical self-completed surveys) (5).

The questionnaire was developed at the University of Thessaly, Department of Biochemistry and Biotechnology (Larissa, Greece) in the framework of the MSc Course on Toxicology and was structured in three sections. The first section addressed demographic information (6 questions); the second investigated the risk/hazard communication of chemicals (14 questions); and the third explored the use and application of personal protective measures (6 questions).

Once the questionnaire was constructed, a multidisciplinary group of professionals that were not participating in the research group was asked to review the document and provide input. This expert group consisted of a toxicologist, a regulatory officer, an officer from the industry and a psychiatrist. The group provided input on the general content and face validity of the questionnaire (Content Validity Ratio-CRV =0.993, P<0.05) (6), which was proven complete and adequate for distribution.

The 103rd General Assembly of Specific Interest (09/03/2016) of the Department of Biochemistry and Biotechnology, University of Thessaly, provided approval for the conduct of the study and distribution of the questionnaire, as part of the dissertation theses of the students M.A. and I.K.

Use of chemicals in the work environment may have consequences on human health, which influences the protection measures that need to be employed and the supportive system in case of accidents or poisonings by health care specialists.

Workers in gas stations are reported to suffer from headaches (32%) and fatigue (20%) (7). In addition, a statistically significant increase in red blood cell counts, haemoglobin, mean corpuscular hemoglobin and platelet counts were found in all self-reported health-related complaints among liquefied petroleum gas workers (8). These symptoms are directly associated with benzene inhalation and workers are found to be exposed regardless of their position in the gas station (9,10).

The prevalence of respiratory and pulmonary problems and even cholangiocarcinoma in printing workers is markedly elevated, with concerns also being applicable for consumers (11–13). In addition the association between exposure to chemicals and asthma and rhinitis remains independent of exposure to dust (14). A meta-analysis of 13 European cohorts spanning births from 1994 to 2011 indicated that employment during pregnancy in occupations classified as possibly or probably exposed to endocrine disruptors was associated with an increased risk of term (15). An association has also been reported between textile industry and different types of cancer including lung, bladder, colorectal and breast cancer (16).

In the present study, 72% of professional users of chemicals face health issues connected to skin and respiratory sensitisation.

Several studies have attempted to elucidate the comprehension of the legislation on chemicals and the hazard communication among workers and the general public (17–21).

Pictograms are the prevailing element in hazard/risk communication. It has been shown that the underlying core elements that enhance understanding of GHS pictograms, which are also essential in developing competent individuals in the use of SDSs, are training and education (22). Cleaning workers found not to be familiar with the pictograms had not been properly informed on the safe usage of chemicals by their employers (20). Age and educational level may impact workers' performance and cognitive process of comprehension of pictograms (19), as evidenced in the present study. Some pictograms are more easily perceived, while others remain controversial, such as GHS05, GHS06 and GHS08, as identified in our study. Similar concerns have been raised regarding the labeling of fragrances (23).

In a meta-analysis of 9 research studies published from 1983 to 2005 evaluating the relationship between literacy and hazard communication three main gaps were recognized regarding lack of learner involvement to improve hazard communication, lack of employer assessment of employee understanding of training provided, and lack of studies assessing retention of the material taught and its application at the worksite (18). In the present study, 30% of the professional users of chemicals tend to perceive the hazard/risk of a chemical after instruction by the employer or the shift supervisor to use PPE. Of note, low PPE compliance persists despite worker awareness of herbicide exposure risks, potentially as a result of the influence of the sex dynamics and social culture (24).

Appropriate work practices and selection and use of PPE are strongly recommended and measurements at the workplace have proven the efficacy thereof (25,26). Nevertheless, use of PPEs is restricted, as observed in the present study. Farmers that are overexposed to pesticides toxicity do not use PPE (27). On the other hand, disposable latex gloves commonly worn by gardeners provide inadequate protection even for contact with pesticides over a short period of time (28). Thus, more emphasis should be given on awareness-raising activities and increase of the communication of chemicals hazard/risk.

Health care specialists are expected to use PPE more extensively to protect themselves from infectious diseases and pathogens (29,30). Nevertheless, these PPEs are not adequate for protection from chemicals and lack of compliance is evident regarding PPEs, even among medical technicians (31). Consequently, the observed almost universal use of PPEs by health care specialists in the present study is potentially misleading. Regarding compliance of the medical staff engagement of the personnel in auditing PPE use and reporting activities may significatnly improve compliance (32).

Health care specialists are often asked to treat cases that are linked with exposure to different chemicals. In the present study, 60% of responders were informed regarding the safe use of chemicals or actions to be undertaken in case of accident. In the latter situation, the National Poisoning Centre is considered the reference point for information for the vast majority of medical doctors. However, the National Poisoning Centers are less often consulted when emergency poisonings are treated in the primary or tertiary care centers (33). Data legally required to be declared to National Poisoning Centers should be harmonized within EU and the new regulatory framework, which is the primary aim of these legal frameworks (34,35).

In conclusion, on a national level, awareness-raising campaigns are imperative (36,37), in collaboration with trade unions and health care professional associations, in order to alert professionals regarding the safe use of chemicals to protect human health and the environment.