1. GUIDELINES FOR HEALTH SURVEILLANCE FOR INORGANIC CHROMIUM

1. GUIDELINES FOR HEALTH SURVEILLANCE FOR INORGANIC CHROMIUM

2. SUPPLEMENTARY INFORMATION ON INORGANIC CHROMIUM

3. REFERENCED DOCUMENTS

4. FURTHER READING

1. GUIDELINES FOR HEALTH SURVEILLANCE FOR INORGANIC CHROMIUM*

BASELINE HEALTH SURVEILLANCE AT TIME OF EMPLOYMENT IN AN INORGANIC CHROMIUM PROCESS

1.Collection of Demographic Data

• Name and unique company identification number.

• Date of birth.

• Sex.

• Address.

• Date of starting company service.

• Descriptive job title. To include the Australian Bureau of Statistics' Australian Standard Classification of Occupations (ASCO)¹ and Australian Standard Industrial Classification (ASIC) ².

• Places of previous employment.

2.Occupational History

• Past work history, including previous exposure to inorganic chromium.

• Potential current exposure.

• Whether suitable personal protective equipment is used for that specific chromium process.

3.Medical History

• Presence of symptoms.

• Smoking history.

4.Physical Examination

With emphasis on the respiratory system and skin.

5.Health Advice

The appointed medical practitioner should inform the employee of the potential health effects associated with exposure to inorganic chromium.

DURING EXPOSURE TO AN INORGANIC CHROMIUM PROCESS

6.Personal Protective Equipment

The availability, type, fit, maintenance and frequency of use of personal protective equipment should be monitored regularly.

7.Workplace Skin Care Program

Participation in a workplace skin care program. Skin inspection of hands and forearms by a 'responsible person' should be conducted weekly, with referral to the appointed medical practitioner when required. The 'responsible person' would need adequate training as part of the inorganic chromium workplace skin care program.

8.Respiratory Symptoms

Respiratory symptoms should be reported to the appointed medical practitioner.

9.Data for Inclusion in Health Records

The following data should be included with the health records of the individual employee:

• Any formal assessments carried out in compliance with the National Occupational Health and Safety Commission's National Model Regulations for the Control of Workplace Hazardous Substances [NOHSC:1005(1994)]³.

• Descriptive job titles, with relevant start and finish dates. Those jobs where exposure has been assessed as significant should be clearly identified.

• Results of atmospheric and personal monitoring, and investigation of results that exceed the national exposure standard.

AT TERMINATION OF EMPLOYMENT IN AN INORGANIC CHROMIUM PROCESS

10.Data that should be Collected

• Date of termination.

• Reason for termination:

  • ill-health (if 'yes', give details),

  • other reasons, and

  • date and cause of death if in service.

2. SUPPLEMENTARY INFORMATION ON INORGANIC CHROMIUM

Chromium exists in a series of oxidation states from -2 valence to +6. The most important stable states are elemental metal (Cr⁰), trivalent (Cr³⁺) and hexavalent (Cr⁶⁺).

WORK ACTIVITIES THAT MAY REPRESENT A HIGH RISK EXPOSURE

Examples of work activities involving inorganic chromium and its compounds which require special attention include:

• welding and hard-facing of stainless steel;

• manual metal arc welding of high chromium steels;

• hard-plating;

• refractory production;

• leather tanning;

• timber preservation (copper chrome arsenic);

• chromate use in the textile industry; and

• chrome pigment use.

POTENTIAL HEALTH EFFECTS FOLLOWING EXPOSURE TO INORGANIC CHROMIUM

The adverse effects of chromium and its inorganic compounds vary according to valence state, water solubility and dose. However, the hexavalent chromium compounds-chromates, dichromates and chromic acid-are of most concern in both acute exposures and chronic exposure to lower concentrations.

Route of Entry into the Body

The routes of inorganic chromium entry into the body are through inhalation, ingestion and percutaneous absorption. Occupational exposure generally occurs through inhalation and dermal contact. The absorption of chromium is dependent on the valence and water-solubility of the chromium compound. Soluble forms of hexavalent chromium are readily absorbed by inhalation. Dermal absorption may also occur. Absorption of water-soluble hexavalent chromium through the gastrointestinal tract is about 10 per cent.

Acute and Chronic Effects

Hexavalent Chromium

Hexavalent chromium compounds on contact with skin, generally as liquids, mists or dusts, may act as both irritants and sensitisers. These also cause corrosive skin and mucous ulcerations, including chrome ulcers and perforation of the nasal septum.

At concentrations below those resulting in irritation, skin sensitivity is the most common effect following exposure to chromium compounds. Allergic dermatitis is well known in printers, cement workers, metal workers, painters, textile workers and leather tanners⁴. Chromate sensitivity, once induced, may prove difficult to deal with in multiple settings and is very persistent once developed.

Inhaled chromium is a respiratory tract irritant, resulting in airway irritation and airway obstruction. Also, exposure by inhalation can cause allergic asthmatic reactions. A single inhalation exposure to highly water-soluble compounds can result in irritation and inflammation of the respiratory tract.

Studies of welders and chromium platers have shown that workers exposed to high levels of chromium show damage to renal tubules. Chronic chromium exposure results in transient renal effects. Nephrotoxicity is the primary cause of death from acute dermal exposure.

Acute chromium exposures can result in hepatic necrosis. Limited data indicate that chronic exposure to chromium compounds can cause hepatic effects.

Trivalent Chromium

Trivalent compounds are generally poorly absorbed through intact skin. However, once the skin is broken, absorption may occur. The trivalent compounds are allergenic, but much less so than the hexavalent compounds.

Carcinogenicity

There is considerable epidemiological evidence that exposures to hexavalent chromium compounds of sparing to high solubility in chromate production, chromium plating and zinc chromate pigment manufacture have led to a clear excess in mortality from lung cancer^5-9. The International Agency for Research on Cancer's⁷ classification for hexavalent chromium compounds is Group 1. According to the International Agency for Research on Cancer, this category is used only when there is sufficient evidence of carcinogenicity in humans.

While metallic chromium and trivalent compounds have an International Agency for Research on Cancer classification of Group 3, there are some mutagenicity tests and an epidemiological study of chrome platers pointing to some carcinogenic potential of soluble chromates, and mutagenicity and epidemiological data do not rule out carcinogenic activity of trivalent compounds. There is also discussion in the literature on the carcinogenic potential of trivalent salts and insoluble chromium compounds which appear to accumulate in human lung tissue after inhalation¹⁰.

Cases of sinonasal cancer have been reported in epidemiological studies of chromate production, chromate pigment production and chromium platers.

Carcinogen Classification

Various hexavalent chromium compounds are listed in the National Commission's List of Designated Hazardous Substances [NOHSC:10005(1994)]¹¹. Chromium-, calcium-, and strontium- chromate are classified as Carcinogen Category 2. Zinc chromate is also listed and is classified as Carcinogen Category 1. According to the National Commission's Approved Criteria for Classifying Hazardous Substances [NOHSC:1008(1994)]¹², a substance is assigned Carcinogen Category 1 if there is sufficient evidence to establish a causal relationship between human exposure and the development of cancer on the basis of epidemiological data, and Carcinogen Category 2 if there is sufficient evidence, on the basis of appropriate long-term animal studies or other relevant information, to provide a strong presumption that human exposure to that substance may result in the development of cancer.

3. REFERENCED DOCUMENTS

1.  
2. Australian Bureau of Statistics, Australian Standard Classification of Occupations: ASCO Coding System, Australian Bureau of Statistics, Canberra, 1993.
3.  
4. Australian Bureau of Statistics, Australian Standard Industrial Classification, Australian Bureau of Statistics, Canberra, 1985.
5.  
6. National Occupational Health and Safety Commission, National Model Regulations for the Control of Workplace Hazardous Substances [NOHSC:1005(1994)], Australian Government Publishing Service, Canberra, 1994.
7.  
8. Baruthio F, 'Toxic Effects of Chromium and its Compounds', Biological Trace Element Research, vol 32, pp 145-53, 1992.
9.  
10. International Programme on Chemical Safety, Environmental Health Criteria 61: Chromium, International Programme on Chemical Safety, World Health Organization, Geneva, 1988.
11.  
12. Gad SC, 'Acute and Chronic Systemic Chromium Toxicity', Science of the Total Environment, vol 86, pp 149-57, 1989.
13.  
14. International Agency for Research on Cancer, IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans, vol 49: Chromium, Nickel and Welding, International Agency for Research on Cancer, Lyon, 1990.
15.  
16. Langard S, 'One Hundred Years of Chromium and Cancer: A Review of Epidemiological Evidence and Selected Case Reports', American Journal of Industrial Medicine, vol 17, pp 189-215, 1990.
17.  
18. Calabrese EJ and Kenyon EM, Air Toxics and Risk Assessment, Lewis Publishers, pp 245-50, 1991.
19.  
20. Norseth T, 'The Carcinogenicity of Chromium and its Salts-editorial', British Journal of Industrial Medicine, vol 43, pp 649-51, 1986.
21.  
22. National Occupational Health and Safety Commission, List of Designated Hazardous Substances [NOHSC:10005(1994)], Australian Government Publishing Service, Canberra, 1994.
23.  
24. National Occupational Health and Safety Commission, Approved Criteria for Classifying Hazardous Substances [NOHSC:1008(1994)], Australian Government Publishing Service, Canberra, 1994.

4. FURTHER READING

Agency for Toxic Substances and Disease Registry, Case Studies in Environmental Medicine 4: Chromium Toxicity, Agency for Toxic Substances and Disease Registry, United States Department of Health and Human Services, Public Health Service, Atlanta, 1990.

Angerer J, Amin W, Heinrich-Ramm R, Szadkowski D and Lehnert G, 'Occupational Chronic Exposure to Metals. I Chromium Exposure of Stainless-steel Welders Biological Monitoring', International Archives on Occupational and Environmental Health, vol 59, pp 503-12, 1987.

Franchini R, Mutti A, Cavatorta E, et al, 'Chromium: Biological Indicators for the Assessment of Human Exposure to Industrial Chemicals', in Alessio L, Berlin A, Boni M and Roi R (eds), Industrial Health and Safety, Commission of the European Communities, Luxembourg, pp 35-51, 1984.

Health and Safety Executive (United Kingdom), Chromium and its Inorganic Compounds-Health and Safety Precautions, Guidance Note EH 2, Health and Safety Executive, London, 1991.

Katz SA and Salem H, 'The Toxicology of Chromium with Respect to its Chemical Speciation: A Review', Journal of Applied Toxicology, vol 13(3), pp 217-24, 1993.

Krieger GR, John B and Sullivan JB, Hazardous Materials Toxicology: Clinical Principles of Environmental Health, Williams and Wilkins, Baltimore, 1992.

National Occupational Health and Safety Commission, National Strategy for the Prevention of Occupational Skin Disorders, Australian Government Publishing Service, Canberra, 1989.

Worksafe Australia, Occupational Diseases of the Skin, Australian Government Publishing Service, Canberra, 1990.

Szafraniec T, 'CCA Exposure in Timber Workers', National Research Workshop on Occupational Skin Disorders and Occupational Cancer, Worksafe Australia, Sydney, 1991.

Von Burg R and Liu D, 'Toxicology Update: Chromium and Hexavalent Chromium', Journal of Applied Toxicology, vol 13(3), pp 225-30, 1993.

* These guidelines set out in a practical manner the minimum requirements for health surveillance and should be read in conjunction with the Introduction to the Guidelines for Health Surveillance [NOHSC:7039(1995)]