Occupations and Hazards Requiring Statutory Medical Examinations

The Ministry of Manpower requires employers to send their employees who are exposed to certain occupational hazards for pre-placement and regular medical examinations.

These medical examinations aren’t general checkups. They are specific tests for the types of hazard involved, and can only be conducted by Designated Workplace Doctors.

These tests allow early detection of occupational diseases and ensure that employees remain fit for such work. They also help you gauge whether existing control measures are effective.

We have a group of Designated Workplace Doctors, and will be happy to guide you along to ensure that you meet MOM’s requirements.

To help you understand better, AcuMed has summarized the type of hazards, industries and also tests required below:

Arsenic or any of its compounds

Industries/Role with Potential Exposure

• Contact with pesticides in wood tanning and wood preservation
• Semiconductor manufacturing
• Alloy (copper / lead) manufacturing
• Smelting of arsenical ores
• Pigment manufacturing
• Anti-fouling paint manufacturing / usage
• Sawing, sanding and burning of wood treated with arsenical preservatives
• Contact with herbicide, pesticide, defoliant, animal and poultry feed with arsenic compounds as additives

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical Examination
• Urine arsenic
• Liver function tests (Blood test)
• Full-sized chest x-ray examination

Medical Tests Required (Every 12 months)

• Clinical examination
• Urine arsenic

Asbestos

Industries/Role with Potential Exposure

• Renovation/ demolition of structures with asbestos material
• Ship breaking and repairs where asbestos is used as structural material
• Insulation work, e.g., replacement and removal of asbestos insulation
• Handling of asbestos products, e.g., fire proof cloth and gaskets
• Repair and replacement of asbestos brake linings by car and bus mechanics

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Full-size chest x-ray examination

Medical Tests Required (Every 36 months)

• Clinical examination
• Full-size chest x-ray examination

Benzene

Industries/Role with Potential Exposure

• Petrochemical workers, E.g. workers involved in manufacturing of benzene
• Petrol retailers, e.g. At oil terminals, service stations, airport terminal workers (contact with aviation gasoline)
• Manufacturing of some types of plastics, synthetic fibers and nylon (cyclohexane), detergents, synthetic resins, butadiene rubber, styrene, phenol, lubricants, dyes and pesticide.
• Laboratories, e.g., use of benzene in analytical techniques
• Work involving use of commercial solvents such as toluene and xylene
• Work involving handling of fuels containing benzene, e.g., vehicle workshops
• Bulk storage terminals contact with petrol and related products, benzene etc
• Handling of benzene-containing waste material
• Sampling of waste water from plants handling benzene

Medical Tests Required (Pre-Placement: Within 3 months of employment)

• Clinical examination
• Haemoglobin (Hb)
• Full blood count–total white blood cells, red blood cells and platelets; Peripheral blood film (PBF

• Urinary tt-muconic acid or s-phenylmercapturic acid

Medical Tests Required (Every 12 months)

• Clinical examination
• Estimation of Urinary tt-muconic acid or s-phenylmercapturic acid

Cadmium or any of its compounds

Industries/Role with Potential Exposure

• Handling of cadmium-containing waste
• Sampling of waste water from plants handling cadmium
• Cadmium electroplating
• Plastics manufacturing, compounding of polyvinyl chloride (PVC)
• Nickel-cadmium battery manufacturing
• Pigment manufacture and use
• Alloy manufacture
• Fungicides use and manufacturing
• Silver brazing, welding on cadmium-containing alloys
• Manufacture of refrigerators, air-conditioners, television picture tubes, semiconductors, photo-cells & fluorescent lamps, and neutron absorber in nuclear reactors
• Jewellery manufacture
• Automobile and aircraft industries
• Smelting and refining of Zn, Pb or Cu ores and scrap processing
• Spray painting using cadmium-containing paints, removal of cadmium paints by blasting or scraping
• Manufacture of cadmium telluride solar panels

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Blood cadmium
• Urine Beta2 – microglobulin (U-β2 m) estimation

Medical Tests Required (Every 12 months)

• Clinical examination
• Blood cadmium
• Urine Beta2 – microglobulin (U-β2 m) estimation

Compressed air environment

Industries/Role with Potential Exposure

• Tunnelling or shaft sinking operations in water bearing strata
• Caisson work on river beds
• Medical lock attendants
• Healthcare staff who oversee medical treatments conducted in hyperbaric chambers
• Checking for leaks within pressurised compartments

Medical Tests Required (Pre-Placement: Within 30 days before employment)

• Clinical Examination
• Height, weight and body fat estimation
• Dipstick urinalysis
• Lung Function tests 
• Resting electrocardiography (35 yrs. and above),
• Treadmill exercise tests (when indicated)
• Audiometry air conduction. If abnormal, to include bone conduction testing and auroscopic examination
• Full blood count and peripheral blood flim
• Test in lock (to 10 meters)
• Full size chest X-ray
• Radiographic examination of shoulder, hip and knee joints

Medical Tests Required (Periodic)

Clinical Examination, under the following senarios:

• Not less than once in every 3 months for working pressures not exceeding 1 bar
• Not less than once in every 4 weeks for working; pressures at or exceeding 1 bar
• Not more than 3 days prior to reemployment in compressed air environment:
• After a worker has suffered from a cold, chest infection, sore throat or earache; and
• After a worker has suffered from any illness or injury necessitating absence from work for more than 3 consecutive days.

• After a worker has not been employed for > 14 consecutive days

12 Monthly Tests

• Height, weight and body fat estimation
• Dipstick urinalysis
• Lung Function tests 
• Resting electrocardiography (35 yrs. and above)
• Treadmill exercise tests (when indicated)
• Audiometry air conduction. If abnormal, to include bone conduction testing and auroscopic examination

12 Monthly or just before stopping work, whichever is earlier (for working pressures at or exceeding 1 bar)

• Radiographic examination of shoulder, hip and knee joints

Excessive Noise

Industries/Role with Potential Exposure

• Shipbuilding & repairing mechanics
• Crushers, drillers, etc. working at quarries
• Engineering works–grinding, sawing involving high velocity equipment
• Iron and steel mills, other heavy metal industries
• Metal working industries, e.g., making of ball and roller bearings, nuts, bolts and screws, metal cans
• Woodworking industry
• Textile industry
• Paper industry
• Engine testing, e.g., jet engines;
• Industries with bottling processes and operations involving cans and metal boxes
• Landscaping – use of leaf blowers, lawnmowers and trimmers

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Audiometry Air Conduction
• Bone conduction and auroscopic examination should be done if any of the air conduction result > 30 dB(A).

Medical Tests Required (Every 12 months)

• Audiometry Air Conduction
• Bone conduction and auroscopic examination should be done if any of the air conduction result > 30 dB(A).

Lead or any of its compounds

Industries/Role with Potential Exposure

• Manufacture and use of lead stabilisers in PVC compounding
• Manufacture of lead-acid storage batteries (accumulators)
• Burning, welding or cutting of lead-coated structures, e.g., shipbreakers and welders
• Manufacture and use of ammunition, e.g., firing range instructors
• Manufacture and use of lead-based paints
• Manufacture of solder and alloys
• Manufacture and use of glazes for porcelain, enamels, tiles

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical Examination
• Haemoglobin level
• For organic lead exposure, urine lead level
• For inorganic lead exposure, blood lead level

Medical Tests Required (Every 6 Months)

• Clinical Examination
• Haemoglobin level
• For organic lead exposure, urine lead level
• For inorganic lead exposure, blood lead level

Manganese or any of its compounds

Industries/Role with Potential Exposure

• Milling of manganese ore
• Manufacture of dry-cell batteries (manganese dioxide)
• Iron and steel industry as a reagent to reduce sulphur and oxygen
• Manganese electroplating
• Manufacture of paints, varnishes, inks and dyes, fertilisers, feed additives, disinfectants and bleaching agents, glass and ceramics (decolouriser and colouring agent)
• Manufacture of matches and fireworks; Manufacture of potassium permanganate;
• Welding operations with manganese-coated rods
• Water treatment
• Exposure to fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT) and mangafodipir to increase octane level of gasoline and improve anti-knock properties of fuel.

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Urine manganese

Medical Tests Required (Every 12 Months)

• Clinical examination
• Urine manganese 

Mercury or any of its compounds

Industries/Role with Potential Exposure

• Electrolytic production of sodium hydroxide, chlorine and acetic acid (as a fluid cathode);
• Manufacture of artificial silk and scientific instruments (e.g., barometers, thermometers), electrical equipment (e.g. batteries and meters), mercury vapour and incandescent lamps, X-ray tubes and radio valves
• Manufacture of amalgams (with copper tin, silver or gold) and solders (with lead and tin)
• Plating of gold, silver, bronze and tin (jewelers)
• Paint and pigment manufacture
• Tanning and dyeing, felt making;
• Used as a catalyst in the chemical industry, e.g., production of acetic acid and acetaldehyde from acetylene
• Taxidermy
• Photography and photogravure
• Mining and extraction; extracting gold and silver from ores
• Laboratories
• Dentistry (i.e., amalgams)

• Brewery (analysis for protein content in malt)

Organic Mercury

• Manufacture and use of certain pharmaceutical products (e.g., antiseptics, germicides, diuretics and contraceptives)
• Manufacture and use of pesticides (e.g., algicides, fungicides, herbicides)
• Manufacture and use of paints and waxes (e.g., antifouling paints, preservatives in paints, latex paints, fungus proofing of fabrics, paper, wood)
• Used as catalysts and alkylating agents in the chemical industry

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• For inorganic mercury exposure, estimation of urinary mercury
• For organic mercury exposure, estimation of blood mercury concentration

Medical Tests Required (Every 12 Months)

• Clinical examination
• For inorganic mercury exposure, estimation of urinary mercury
• For organic mercury exposure, estimation of blood mercury concentration

Organophosphates

Industries/Role with Potential Exposure

• Horticulture–gardeners, greenhouse workers;
• Agriculture–garden pest control operators, farmers;
• Vector control operators;
• Formulation and manufacture of organophosphates, e.g., insecticide sprays;
• Laboratory workers analysing organophosphates; and packing and redistribution of organophosphates.

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Red blood cell acetylcholinesterase estimation

• Plasma cholinesterase estimation.

Medical Tests Required (Every 6 Months)

• Clinical examination
• Red blood cell acetylcholinesterase estimation

Perchloroethylene

Industries/Role with Potential Exposure

• Dry cleaning in laundries;
• Degreasing and cleaning of metal parts and equipment in metalworking, automotive, aircraft, aerospace industries and shipyards;
• Cleaning of lenses in the optical industry

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Mid of workweek end-of-shift urinary trichloroacetic acid (U-TCA) + Liver Function Tests (Serum bilirubin, Alkaline phosphatase, Asparate aminotransferase, Alanine aminotransferase and Gamma glutamyl transferase).
  For exposures that are irregular or intermittent, the test should be done at the end of the exposure period.

Medical Tests Required (Every 12 Months)

• Clinical examination
• Urinary trichloroacetic acid (U-TCA)

Cotton Dust

Industries/Role with Potential Exposure

• Raw cotton processing in textile industry
• Carding, opening, spinning, winding, drawing, twisting, weaving, and harvesting of cotton. (separating fibers and forming them into bundles of roughly parallel fibers)
• Raw cotton processing in other industries, e.g., preparation of substrate for growing of mushrooms

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical history and examination
• Pre- shift lung function test on the first day of the working week
• Post-shift lung function test to be done after at least 6 hours of exposure on the same day

Medical Tests Required (Every 12 Months)

• Clinical history and examination
• Pre- shift lung function test on the first day of the working week
• Post-shift lung function test to be done after at least 6 hours of exposure on the same day

Silica

Industries/Role with Potential Exposure

• Mining, quarrying and tunnelling of siliceous rocks (e.g. granite, sandstone, slate, mica, silica containing coal or metal ores);
• Abrasive blasting using siliceous grains (e.g., sandstone, sand, quartzite and flint)
• Stone cutting, dressing, polishing, cleaning and monumental masonry (including tombstone engraving) using granite and sandstone
• Construction (e.g., jack hammering, drilling of silica or silicon dioxide-containing material like sand, sandstone, quartz and granite)
• Maintenance and repair of refractories (furnace linings)
• Manufacture of ceramics (chinaware, porcelain, earthenware) and refractories
• Foundries (mould breaking and fettling)
• Rubber milling (using calcium carbonate containing silica)
• Enameling using quartz, feldspar, metal oxides and carbonates
• Manufacturing of abrasive soaps

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Full size chest x-ray examination.

Medical Tests Required (Every 36 Months)

• Clinical examination
• Full size chest x-ray examination.

Tar, Pitch, Bitumen & Creosote

Industries/Role with Potential Exposure

• Manufacture of coal tar, pitch, bitumen and creosote (Coke oven industries)
• Coal gasification
• Coke production
• Water proofing of wood, making of roofing and insulating materials
• Lining irrigation canals and reservoirs
• Manufacture of dyestuff (e.g., carbon black; Manufacture of paints)
• Chemical feedstock for the production of benzene, toluene, xylene, phenol
• Sealing agents (e.g., in battery manufacture)
• Lubricant for die moulds

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination

Medical Tests Required (Every 12 Months)

• Clinical examination

Trichloroethylene

Industries/Role with Potential Exposure

• Workers involved in vapour degreasing and cold cleaning of metal parts in metal fabricating, automotive, aircraft and aerospace industries
• Usage for cleaning of lenses in optical industry
• Usage as solvent for extraction of waxes, fats, resins and oils
• Usage as a solvent or chemical intermediate in printing inks, varnishes, adhesives, paints, lacquers, rug cleaners and disinfectants

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Urinary trichloroacetic acid
• Liver function tests

Medical Tests Required (Every 12 Months)

• Clinical examination
• Urinary trichloroacetic acid

Vinyl Chloride Monomer

Industries/Role with Potential Exposure

• Production of polyvinyl chloride resins (workers who clean and maintain the reactors are especially at risk)
• Production of vinyl chloride- vinyl acetate copolymers
• Storage of Vinyl Chloride Monomer
• Sampling and analysis of Vinyl Chloride Monomer

Medical Tests Required (Pre-Placement: Within 3 months of exposure)

• Clinical examination
• Liver function tests
• Hepatitis B and C serology

Medical Tests Required (Every 12 Months)

• Clinical examination
• Liver function tests

The following information serves as a summary guide for the Statutory Medical Examinations.

For more details, you can contact our clinics.

Content adapted from: WSHC-Statutory Medical Examinations https://www.wshc.sg/files/wshc/upload/cms/file/2014/WSH_Guidelines_Statutory_Medical_Examinations_2013.pdf