Workplace Exposure Standards
Consideration Paper on Lowering the Workplace Exposure Standard for Formaldehyde
Feedback and DoL Response
| Topic | Sample question or comment from submission | DoL response |
|---|---|---|
| Sensory versus tissue irritation | Care needs to be taken when discussing health effects of formaldehyde to distinguish between sensory irritation and tissue irritation, which are two very different effects. | That is a fair comment; and it may be preferable to refer to the latter as tissue inflammation, which reduces the chance of confusion. However both these effects are important; while it is critically important to minimise (and ideally abolish) risk of Upper Respiratory Tract (URT) cancer by minimising tissue irritation, it is also justifiable to minimise or prevent subjective irritant symptoms. (While there is a strong school of thought that achievement of the latter will also achieve the former, that is not a universal view). |
| Extended work-shifts | Based on the review by Verma (2000) and others, FCANZ (The Formaldehyde Council of Australia and New Zealand) believes that the most suitable correction factor for adjustment of the TWA for extended work shifts is 1. | The committee felt that for a chemical considered a probable or definite human carcinogen, the total dose received remains a primary consideration. (While with formaldehyde there is some evidence that concentration is more important; total dose cannot be ignored, given that mechanistic controversies appear not to be fully resolved). For any given (average) concentration, the total dose received by the upper respiratory tract (the target organ of most concern) will clearly be proportional to the duration of exposure, which should therefore be taken into account. The Verma (2000) paper discusses various models designed to correct for any risks of increases in body burden of toxicants from “unusual” work schedules. Formaldehyde is not mentioned, and indeed there seems no strong reason to “correct” for accumulation as it is metabolised so quickly. However the concern with formaldehyde mainly relates to the tissues of first contact (“pre-metabolism”), as opposed to the blood or more distant site toxicity, (the leukaemia issue arguably remains unresolved). While acknowledging the technical complexities and resulting uncertainties, the committee was uncomfortable with the underlying implication (of an “adjustment” factor of just one), that for a putative carcinogen, a longer exposure carried no more risk than a shorter exposure. On the other hand, there is an alternative approach for carcinogens, where one looks not at the duration of individual shifts, but rather the total duration of the shift “sequence”; per week, month, or year. In that respect, one would consider four 12 hour shifts equivalent to six 8 hour shifts, and just 1.2 times greater than the traditional forty hour week. |
| Respiratory protection | The six paragraphs on Respiratory Protective Equipment (RPE) are confusing and make no real conclusion. It appears to be a mix-match of how to assess inward leakage. However, does not flow, enabling the reason to decipher how and where the measurement is to be conducted. | The objective of this section was to clarify where WES apply – inside the respirator or outside. WES apply to the air the worker is breathing, thus if any air containing hazardous substances can enter the mask, then the quality of the air inside the mask is what should be compared to the WES. As it is not practical to test the air inside the mask, except under testing conditions (as opposed to working conditions), the air outside the mask is measured, and the protection factor of the mask is applied to determine an estimated air concentration inside the mask. Thus the air concentration (outside the mask) must be used to determine which type of respirator is needed. AS/NZS 1715:2009 Selection, use and maintenance of respiratory protective equipment should be consulted for guidance on respiratory protection. |
| Health effects at low levels | Although the literature review stated that exposure led to some acute effects of health, there are no exposure limits cited for when these effects take place or how the reduction to 0.3ppm will prevent such effects. DECOS report (2006) cites statistical significance: “increased risk not demonstrated with low exposures...” Change will add no improvement to worker safety. The information has not demonstrated that the proposed WES will be more effective than existing WES in minimising cancer risk because the risk is already very low and unlikely to be elevated compared with general population at levels below 2ppm. 2009 WorkSafe British Columbia review concluded that 1ppm is NOAEL for nasal injury in humans, further supported by fact that symptoms disappear quickly, underlying non-adversity of irritating effects at low concentrations. Why is NZ requiring a lower level? Rationale for imposing WES-TWA to 0.3ppm not valid as overseas data is not valid in NZ and 30 years out of date. |
There is variance in the literature regarding the concentration-response relationships of subjective irritant effects; sources of variation include duration of exposure and individual “susceptibility” factors. However, there is enough evidence to conclude that at least for some individuals, decreasing exposures from a hitherto effectively permitted constant level of 0.99ppm down to the TWA and STEL proposed, will result in considerable reduction in perceived irritation. Worker comfort (as well as safety) is a legitimate consideration in the setting of WES. The concentration-response relationship for upper respiratory tract cancer in humans is also not completely clear. While some epidemiological studies certainly suggest risk increases substantially above about 2ppm, individual study sizes (+/- exposure data) have arguably been insufficient to reliably assess (and eliminate) risk at much lower exposures. Even very low workplace carcinogenic risks are considered unacceptable; and some predictive models suggest such risks cannot be completely excluded with formaldehyde levels of 1ppm (or indeed lower than that). With suspected or even potential carcinogens, minimising levels to the extent feasible can always be justified from a safety perspective. |
| Carcinogenic effects | Has been investigated as an industrial hazard for over 50 years especially for carcinogenic properties – epidemiological research has not provided credible evidence for any carcinogenic risk to workers in modern industry | International Agency for Research on Cancer (IARC) concluded there is sufficient evidence in humans and experimental animals for the carcinogenicity of formaldehyde. The United States Environmental Protection Agency (USEPA) in their 2010 draft ‘Toxicological review of formaldehyde – Inhalation Assessment’ regards that on the weight of evidence, formaldehyde is a human carcinogen. In New Zealand formaldehyde is classified as a Class 6.7A substance under the HSNO Act (6.7A = substance that are known or presumed carcinogens). |
| Health based versus feasibility levels | The paper only considers medical aspects of exposure. Some of the data in the report for other countries is the medical recommended levels, not the regulatory level which are set higher to allow for workable cost benefit consideration. Proposed change should be subjected to full regulatory impact assessment analysis with close industry involvement. The Department of Labour (DoL) has not demonstrated that the proposed standard will be any more effective than the existing one for protecting people from adverse health effects. DoL should not change WES until full and comprehensive analysis on socio-economical impact is done focussing on most cost effective management practices |
The department considers industry is in the best position to demonstrate cost-benefit analysis because:
|
| Formaldehyde users outside of timber industry | [Funeral and embalming industry members] are happy to look at the current WES for formaldehyde in the funeral industry but would prefer to work with DoL to develop industry specific WES. Also concerned about the possible blurring of the lines between the use of formaldehyde and wood dust, and their impact on those working with formaldehyde in the timber industry, and concern that initial discussion papers were aimed at timber industry. | Allowing a less stringent WES for one industry over another would contradict to the objective of WES (to define a level that will achieve freedom from adverse health effects). Some toxicology studies have adjusted for possible confounding effects of wood dust and still found increased risk of adverse effects from formaldehyde exposure. However, the Department is happy to work with the funeral and embalming industry in producing strategies and guidance for Health and Safety Inspectors and the industry. |
| WES under HSNO | It’s ERMA’s responsibility to set exposure limits. Although WES are covered by the HSNO Act, ERMA has discretion for WES to be guidelines only. This has been raised on a number of occasions but the report does not address this. Why was section 77B(5)(b)(ii) left out? It states proposed exposure limit is more cost-effective in terms of its effect on the management, use and risks of substance. |
The process of reviewing WES was undertaken with ERMA’s full participation and in a manner compliant with the requirements of s77B of the HSNO Act. The Department and ERMA are currently finalising an operational agreement under which the Authority is ‘providing a method’ to DoL for the setting of WES as specified under s77B (1)(b) and (3)(b). At this stage, the reviewed WES are guideline values until the Authority has formally adopted them as HSNO controls, at which point the Authority will determine whether or not the limits should be guidelines only. The subsections under 77B(5)(b) are i or ii or iii (any or all can be selected). |
| Sampling methods | No guidance provided on suitable or acceptable test methods. | Acceptable methods would include OSHA, NIOSH, HSE and EPA methods for airborne formaldehyde. Exposure monitoring should be carried out by competent persons with appropriate expertise in sampling methodology and interpretation of results. |
| Enforcing WES | How is DoL going to enforce WES – what monitoring frequency and test method is DoL recommending as standard? | See above re sampling methods. Monitoring frequency can depend on a number of factors e.g. concentrations measured, changes to processes, reports of adverse health effects. Monitoring frequency should be determined by the company in conjunction with a competent person e.g. competent occupational hygienist. Employers have a duty under Section 10(2)(c) of the Health and Safety in Employment Act 1992 to take all practicable steps to monitor employees exposure to the hazard. The objective of monitoring exposure is to enable the assessment of risk and determine appropriate control methods. The department’s health and safety inspectors assess compliance with the Act and where minimisation is applied, will assess compliance with Section 10(2)(c). In a situation where formaldehyde exposures exceeded the WES on repeated occasions, and the results had statistical validity, and the employer was not taking steps to control the hazard, then the WES guidelines may be used to support an inspectors conclusion that the employer is not taking all practicable steps to manage the hazard under the HSE Act. Under Section 29 of the Hazardous Substances (Classes 6, 8 and 9 Controls) Regulations, a person in charge of a workplace has a duty to ensure no person is exposed to concentrations exceeding the WES. At this stage, the new formaldehyde WES are guideline values until the Authority has formally adopted them as HSNO controls, at which point the Authority will determine whether or not the limits should be guidelines only. |
| Managing exposure | Lowering of WES could force industry to use replacement chemicals with higher risk, less well understood and not covered by current WES. | This approach contradicts the legal requirement under the Health and Safety in Employment Act to take all practicable steps to:
|
