Clothing dye study

A study of airborne hazardous substance exposures in seven clothing and three footwear manufacturers found the use of dyestuffs in clothing and solvents in footwear to be the key areas of concern.

The study, commissioned by the Department of Labour and conducted by Christchurch-based consultancy Chemsafety, consisted of a walk-through hazard survey and airborne exposure measurements at each of the ten sites.

Chemsafety’s Bridgette Jennings told delegates at the NZOHNA/NZISM annual conference that the research team were surprised by the confusion surrounding the use of dyestuffs, as the safety data sheets were often unclear and employers were confused about the protective measures required.

The ten clothing manufacturers included smaller operations which bought in fabric by the roll, and larger operations which knitted and dyed their own fabrics. The four airborne hazards were inhalable dust, formaldehyde (from treated fabrics), oil mist (from knitting machines with oil reservoirs, often with visible oil deposits on machine parts), and in the dyehouse from dye powders.

Levels of inhalable dust and oil mist were all found to be well below the Workplace Exposure Standards, with the highest levels recorded reaching only 21% of the WES. For dye powders comparison with the WES was difficult because of the wide variation in chemical formulations used.

“They are more hazardous than the standard suggests,” said Jennings, who found few effective control measures in place, despite SDS suggesting every dye in use was sensitising, and a highest reading of 2.6mg per cubic metre for hydrosulphite.

In one plant local extraction was used over the dye weighing area, but turning it on was seen as optional. PPE was sometimes supplied to staff, but use was often disregarded by staff.

The researchers recommendation to DoL is that specific controls are put in place for use of dyestuffs in clothing manufacturers, particularly in the weighing area.

In the footwear manufacturers the airborne hazards were inhalable dust (all sewing and skiving machines had local extraction), isocyanates (from polyurethane glues), and solvents (from adhesives and for cleaning).

Dust and isocyanate levels were well below the WES, but solvents were more of a problem. While the highest solvent exposure was 67% of the WES limit, there was significant variability and little awareness that solvent exposure is harmful.

“People are aware that isocyanates are nasty, but not aware of the hazards of solvents,” said Jennings, who recommends more effective controls for solvent exposure and operator protection

This story appeared in Safeguard Update newsletter of 5 October.

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